[Clang][PowerPC] __builtin_ppc_test_data_class with fewer than 2 arguments triggers Assertion `Arg < getNumArgs() && "Arg access out of range!"' failed.

Reproducer:

A fuzzing tool generated the following test case:
https://godbolt.org/z/dcG8xzKMo

```c++
int test_builtin_ppc_test_data_class_d() {
float d = 1;
return __builtin_ppc_test_data_class(d);
}
```

With Clang trunk and:

```
--target=powerpc64le-linux-gnu -mcpu=power9
```

Clang triggers:

```
clang++: /root/llvm-project/llvm/tools/clang/include/clang/AST/Expr.h:3159: clang::Expr* clang::CallExpr::getArg(unsigned int): Assertion `Arg < getNumArgs() && "Arg access out of range!"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and dumped files.
Stack dump:
0. Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics --target=powerpc64le-linux-gnu -mcpu=power9
1. :3:41: current parser token ')'
2. :1:42: parsing function body 'test_builtin_ppc_test_data_class_d'
3. :1:42: in compound statement ('{}')
#0 0x000000000448ebf8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x448ebf8)
#1 0x000000000448baa4 llvm::sys::RunSignalHandlers() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x448baa4)
#2 0x000000000448c0dc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x448c0dc)
#3 0x00000000043ca9d8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#4 0x000079579be45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#5 0x000079579be9ec0c pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x9ec0c)
#6 0x000079579be4527e raise (/lib/x86_64-linux-gnu/libc.so.6+0x4527e)
#7 0x000079579be288ff abort (/lib/x86_64-linux-gnu/libc.so.6+0x288ff)
#8 0x000079579be2881b (/lib/x86_64-linux-gnu/libc.so.6+0x2881b)
#9 0x000079579be3b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
#10 0x0000000006f70e1a (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6f70e1a)
#11 0x000000000703a009 clang::Sema::BuiltinConstantArgRange(clang::CallExpr*, unsigned int, int, int, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x703a009)
#12 0x0000000007744775 clang::SemaPPC::CheckPPCBuiltinFunctionCall(clang::TargetInfo const&, unsigned int, clang::CallExpr*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7744775)
#13 0x00000000070675be clang::Sema::CheckBuiltinFunctionCall(clang::FunctionDecl*, unsigned int, clang::CallExpr*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x70675be)
#14 0x0000000007382fdb clang::Sema::BuildResolvedCallExpr(clang::Expr*, clang::NamedDecl*, clang::SourceLocation, llvm::ArrayRef, clang::SourceLocation, clang::Expr*, bool, clang::CallExpr::ADLCallKind) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7382fdb)
#15 0x000000000737d94c clang::Sema::BuildCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef, clang::SourceLocation, clang::Expr*, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x737d94c)
#16 0x0000000007383eaf clang::Sema::ActOnCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef, clang::SourceLocation, clang::Expr*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7383eaf)
#17 0x0000000006e432c3 clang::Parser::ParsePostfixExpressionSuffix(clang::ActionResult) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6e432c3)
#18 0x0000000006e3bc9a clang::Parser::ParseCastExpression(clang::CastParseKind, bool, bool&, clang::TypoCorrectionTypeBehavior, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6e3bc9a)
#19 0x0000000006e3df47 clang::Parser::ParseCastExpression(clang::CastParseKind, bool, clang::TypoCorrectionTypeBehavior, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6e3df47)
#20 0x0000000006e3dfd9 clang::Parser::ParseAssignmentExpression(clang::TypoCorrectionTypeBehavior) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6e3dfd9)
#21 0x0000000006e428c9 clang::Parser::ParseExpression(clang::TypoCorrectionTypeBehavior) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6e428c9)
#22 0x0000000006ec2022 clang::Parser::ParseReturnStatement() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ec2022)
#23 0x0000000006ec5f6d clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::LabelDecl*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ec5f6d)
#24 0x0000000006ec7139 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::LabelDecl*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ec7139)
#25 0x0000000006ecf655 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ecf655)
#26 0x0000000006ecfe9a clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ecfe9a)
#27 0x0000000006dccf8d clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6dccf8d)
#28 0x0000000006e169f6 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6e169f6)
#29 0x0000000006dc13bb clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6dc13bb)
#30 0x0000000006dc1baf clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6dc1baf)
#31 0x0000000006dce368 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6dce368)
#32 0x0000000006dcf2c5 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6dcf2c5)
#33 0x0000000006dcf6b0 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6dcf6b0)
#34 0x0000000006dac1ec clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6dac1ec)
#35 0x0000000004f92ef8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4f92ef8)
#36 0x00000000052bd7b8 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x52bd7b8)
#37 0x000000000524baed clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x524baed)
#38 0x00000000053927ed clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x53927ed)
#39 0x0000000000dae91c cc1_main(llvm::ArrayRef, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdae91c)
#40 0x0000000000da553a ExecuteCC1Tool(llvm::SmallVectorImpl&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr) driver.cpp:0:0
#41 0x0000000000da56bd int llvm::function_ref&)>::callback_fn&)>(long, llvm::SmallVectorImpl&) driver.cpp:0:0
#42 0x000000000500bbc9 void llvm::function_ref::callback_fn>, std::__cxx11::basic_string, std::allocator>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#43 0x00000000043cae14 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x43cae14)
#44 0x000000000500c735 clang::driver::CC1Command::Execute(llvm::ArrayRef>, std::__cxx11::basic_string, std::allocator>*, bool*) const (.part.0) Job.cpp:0:0
#45 0x0000000004fc43e2 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4fc43e2)
#46 0x0000000004fc8d47 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4fc8d47)
#47 0x0000000004fd3415 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4fd3415)
#48 0x0000000000daae1a clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdaae1a)
#49 0x0000000000cc6b4a main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcc6b4a)
#50 0x000079579be2a1ca (/lib/x86_64-linux-gnu/libc.so.6+0x2a1ca)
#51 0x000079579be2a28b __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2a28b)
#52 0x0000000000da4ee5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xda4ee5)
clang++: error: clang frontend command failed due to signal (use -v to see invocation)
Compiler returned: 134
```

The crash is reproducible with Clang trunk and was first reproducible with Clang 14.

This issue appears to be related to #217023 and #217035, where other PowerPC builtins also fail to validate argument counts before accessing builtin arguments. Since the earliest affected versions and builtin types are different, I reported this issue separately rather than combining the reports.

Start with clang::SemaPPC::CheckPPCBuiltinFunctionCall, identified in the crash stack, and reproduce the issue with the provided __builtin_ppc_test_data_class call using the PowerPC target options. Trace how the builtin arguments are validated before access. Done means the reproducer no longer triggers an assertion and instead receives appropriate argument-count handling.

Written by the indexing model from the issue text.