[X86-64] Clang ICE when inline asm moves __int128 to RAX

### Link for quick verification: https://godbolt.org/z/M8voEcjr6
```c
#include
void force_hard_register(__int128 val) {
__asm__("movq %0, %%rax" : /* no outputs */ : "g"(val));
}

int main() {
__int128 b = 0xABCDEFABBAFEDCBAUL;
force_hard_register(b);
}
```
Go back to `clang 3.1 (assertions)`. And it can only be reproducible with the optimazation flag.
The crash occurs in `LowerAsmOperandForConstraint` while handling a `__int128` value in inline assembly with a 64-bit register constraint
(eg. `RAX`).
## Stack dump
```console
clang++: /root/llvm-project/llvm/include/llvm/ADT/APInt.h:1566: int64_t llvm::APInt::getSExtValue() const: Assertion `getSignificantBits() <= 64 && "Too many bits for int64_t"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
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 -O3
1. parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module ''.
4. Running pass 'X86 DAG->DAG Instruction Selection' on function '@main'
#0 0x0000000004301458 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4301458)
#1 0x00000000042fe884 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x42fe884)
#2 0x0000000004243628 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#3 0x000074c801242520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#4 0x000074c8012969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
#5 0x000074c801242476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
#6 0x000074c8012287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
#7 0x000074c80122871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
#8 0x000074c801239e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#9 0x0000000000e49efe (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xe49efe)
#10 0x0000000002d7d8b4 llvm::X86TargetLowering::LowerAsmOperandForConstraint(llvm::SDValue, llvm::StringRef, std::vector>&, llvm::SelectionDAG&) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x2d7d8b4)
#11 0x00000000059e47e2 llvm::TargetLowering::ComputeConstraintToUse(llvm::TargetLowering::AsmOperandInfo&, llvm::SDValue, llvm::SelectionDAG*) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x59e47e2)
#12 0x000000000589d200 llvm::SelectionDAGBuilder::visitInlineAsm(llvm::CallBase const&, llvm::BasicBlock const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x589d200)
#13 0x00000000058bc13f llvm::SelectionDAGBuilder::visitCall(llvm::CallInst const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x58bc13f)
#14 0x00000000058d0502 llvm::SelectionDAGBuilder::visit(llvm::Instruction const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x58d0502)
#15 0x0000000005962fcd llvm::SelectionDAGISel::SelectBasicBlock(llvm::ilist_iterator_w_bits, false, true>, llvm::ilist_iterator_w_bits, false, true>, bool&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5962fcd)
#16 0x0000000005963a38 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5963a38)
#17 0x000000000596556c llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x596556c)
#18 0x0000000005950dff llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5950dff)
#19 0x0000000003598cf9 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
#20 0x0000000003bef316 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3bef316)
#21 0x0000000003bef6c1 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3bef6c1)
#22 0x0000000003beff2f llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3beff2f)
#23 0x00000000045c2e3c (anonymous namespace)::EmitAssemblyHelper::RunCodegenPipeline(clang::BackendAction, std::unique_ptr>&, std::unique_ptr>&) BackendUtil.cpp:0:0
#24 0x00000000045c3770 clang::emitBackendOutput(clang::CompilerInstance&, clang::CodeGenOptions&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr, std::unique_ptr>, clang::BackendConsumer*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x45c3770)
#25 0x0000000004c62327 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c62327)
#26 0x0000000006a1e5ac clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6a1e5ac)
#27 0x0000000004c62788 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c62788)
#28 0x0000000004f58e05 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4f58e05)
#29 0x0000000004ed909e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4ed909e)
#30 0x000000000505318d clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x505318d)
#31 0x0000000000de63ec cc1_main(llvm::ArrayRef, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xde63ec)
#32 0x0000000000ddce3a ExecuteCC1Tool(llvm::SmallVectorImpl&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr) driver.cpp:0:0
#33 0x0000000000ddcfbd int llvm::function_ref&)>::callback_fn&)>(long, llvm::SmallVectorImpl&) driver.cpp:0:0
#34 0x0000000004cd4e59 void llvm::function_ref::callback_fn>, std::__cxx11::basic_string, std::allocator>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#35 0x0000000004243ac4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4243ac4)
#36 0x0000000004cd546f clang::driver::CC1Command::Execute(llvm::ArrayRef>, std::__cxx11::basic_string, std::allocator>*, bool*) const (.part.0) Job.cpp:0:0
#37 0x0000000004c95f52 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c95f52)
#38 0x0000000004c96efe clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c96efe)
#39 0x0000000004c9e355 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c9e355)
#40 0x0000000000de27e1 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xde27e1)
#41 0x0000000000c8d114 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc8d114)
#42 0x000074c801229d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#43 0x000074c801229e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#44 0x0000000000ddc8d5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xddc8d5)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```

Start with the Godbolt reproduction and the -O3 command shown in the report. Read the X86TargetLowering::LowerAsmOperandForConstraint stack-frame entry and trace how the __int128 inline-assembly operand is handled for the RAX constraint. Done means the provided program no longer triggers the assertion or exits with code 134.

Written by the indexing model from the issue text.