[clang][DebugInfo] Assertion `SizeInBits >= OffsetInBits - FragmentOffset && "size underflow"' failed.

Reproducer:
https://godbolt.org/z/5bjqq7ord
```c
void foo(void) {
char arr[0x100000000];
char *ptr = arr + ~0u/2;
*ptr = 42;
}
```

Backtrace:
```console
clang++: /root/llvm-project/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp:542: bool llvm::DwarfExpression::addExpression(llvm::DIExpressionCursor&&, llvm::function_ref): Assertion `SizeInBits >= OffsetInBits - FragmentOffset && "size underflow"' 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 -x c -std=c89 -O1 -g
1. parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module ''.
4. Running pass 'X86 Assembly Printer' on function '@foo'
#0 0x0000000004284618 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4284618)
#1 0x0000000004281a44 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4281a44)
#2 0x00000000041c5448 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#3 0x0000707e82442520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#4 0x0000707e824969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
#5 0x0000707e82442476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
#6 0x0000707e824287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
#7 0x0000707e8242871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
#8 0x0000707e82439e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#9 0x000000000521891a llvm::DwarfExpression::addExpression(llvm::DIExpressionCursor&&, llvm::function_ref) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x521891a)
#10 0x00000000052189b5 llvm::DwarfExpression::addExpression(llvm::DIExpressionCursor&&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x52189b5)
#11 0x000000000527dc81 llvm::DwarfCompileUnit::applyConcreteDbgVariableAttributes(llvm::Loc::Single const&, llvm::DbgVariable const&, llvm::DIE&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x527dc81)
#12 0x000000000527d228 llvm::DwarfCompileUnit::constructVariableDIE(llvm::DbgVariable&, llvm::LexicalScope const&, llvm::DIE*&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x527d228)
#13 0x0000000005283972 llvm::DwarfCompileUnit::createAndAddScopeChildren(llvm::LexicalScope*, llvm::DIE&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5283972)
#14 0x0000000005287226 llvm::DwarfCompileUnit::constructSubprogramScopeDIE(llvm::DISubprogram const*, llvm::Function const&, llvm::LexicalScope*, llvm::MCSymbol*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5287226)
#15 0x0000000005211bc9 llvm::DwarfDebug::endFunctionImpl(llvm::MachineFunction const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5211bc9)
#16 0x00000000051d5427 llvm::DebugHandlerBase::endFunction(llvm::MachineFunction const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51d5427)
#17 0x00000000051ce8aa llvm::AsmPrinter::emitFunctionBody() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51ce8aa)
#18 0x0000000002a5a4f4 llvm::X86AsmPrinter::runOnMachineFunction(llvm::MachineFunction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x2a5a4f4)
#19 0x0000000003536099 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
#20 0x0000000003b7d856 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b7d856)
#21 0x0000000003b7dc01 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b7dc01)
#22 0x0000000003b7e46f llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b7e46f)
#23 0x0000000004543306 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+++0x4543306)
#24 0x0000000004bd4207 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4bd4207)
#25 0x000000000697194c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x697194c)
#26 0x0000000004bd4668 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4bd4668)
#27 0x0000000004ebfd05 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4ebfd05)
#28 0x0000000004e4006e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4e4006e)
#29 0x0000000004fb8d6d clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4fb8d6d)
#30 0x0000000000dc8450 cc1_main(llvm::ArrayRef, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdc8450)
#31 0x0000000000dbeeca ExecuteCC1Tool(llvm::SmallVectorImpl&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr) driver.cpp:0:0
#32 0x0000000000dbf04d int llvm::function_ref&)>::callback_fn&)>(long, llvm::SmallVectorImpl&) driver.cpp:0:0
#33 0x0000000004c3ce59 void llvm::function_ref::callback_fn>, std::__cxx11::basic_string, std::allocator>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#34 0x00000000041c58e4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x41c58e4)
#35 0x0000000004c3d46f clang::driver::CC1Command::Execute(llvm::ArrayRef>, std::__cxx11::basic_string, std::allocator>*, bool*) const (.part.0) Job.cpp:0:0
#36 0x0000000004bfdc62 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4bfdc62)
#37 0x0000000004bfec0e clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4bfec0e)
#38 0x0000000004c06045 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c06045)
#39 0x0000000000dc4871 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdc4871)
#40 0x0000000000c73414 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc73414)
#41 0x0000707e82429d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#42 0x0000707e82429e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#43 0x0000000000dbe965 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xdbe965)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```

Reproduce the assertion with the provided C program using Clang with -g and -O1, then inspect llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp around line 542 and the DwarfExpression::addExpression stack frame. Trace how the large array offset produces the underflow, and confirm that compiling the reproducer completes without the assertion once corrected.

Written by the indexing model from the issue text.