Silence warnings when compiling x86 with latest MSVC

[aganea]

Summary

When using Visual Studio 2019 16.5.4, and targetting 32-bit, before this patch we were seeing:

[1378/3007] Building CXX object lib\ProfileData\CMakeFiles\LLVMProfileData.dir\InstrProfReader.cpp.obj
F:\llvm-project\llvm\lib\ProfileData\InstrProfReader.cpp(426): warning C4018: '>': signed/unsigned mismatch
F:\llvm-project\llvm\lib\ProfileData\InstrProfReader.cpp(415): note: while compiling class template member function 'llvm::Error llvm::RawInstrProfReader<uint32_t>::readRawCounts(llvm::InstrProfRecord &)'
F:\llvm-project\llvm\lib\ProfileData\InstrProfReader.cpp(491): note: see reference to function template instantiation 'llvm::Error llvm::RawInstrProfReader<uint32_t>::readRawCounts(llvm::InstrProfRecord &)' being compiled
F:\llvm-project\llvm\lib\ProfileData\InstrProfReader.cpp(78): note: see reference to class template instantiation 'llvm::RawInstrProfReader<uint32_t>' being compiled
F:\llvm-project\llvm\lib\ProfileData\InstrProfReader.cpp(430): warning C4018: '>': signed/unsigned mismatch

And:

[2060/3007] Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\ParsedAttr.cpp.obj
F:\llvm-project\clang\lib\Sema\ParsedAttr.cpp(114): warning C4018: '<': signed/unsigned mismatch

I can commit the two files independently if you prefer.

[vsk]

Thanks, this lgtm. If you could split this up into two commits before landing it, I'd appreciate it.

[aganea]

Will do, thank you for your time!

clang/lib/Sema/ParsedAttr.cpp

 namespace {
 
 #include "clang/Sema/AttrParsedAttrImpl.inc"
 
 } // namespace
 
 const ParsedAttrInfo &ParsedAttrInfo::get(const AttributeCommonInfo &A) {
   // If we have a ParsedAttrInfo for this ParsedAttr then return that.
-  if (A.getParsedKind() < llvm::array_lengthof(AttrInfoMap))
+  if ((size_t)A.getParsedKind() < llvm::array_lengthof(AttrInfoMap))
     return *AttrInfoMap[A.getParsedKind()];
 
   // If this is an ignored attribute then return an appropriate ParsedAttrInfo.
   static const ParsedAttrInfo IgnoredParsedAttrInfo(
       AttributeCommonInfo::IgnoredAttribute);
   if (A.getParsedKind() == AttributeCommonInfo::IgnoredAttribute)
     return IgnoredParsedAttrInfo;