[OpenCL] Fix version reporting of C++ for OpenCL 2021

[Topotuna]

Summary

C++ for OpenCL version 2021 and later are expected to consist of a
major version number only. Therefore, a different constructor for
VersionTuple needs to be called when reporting language version.

[Anastasia]

LGTM! Thanks!

I imagine you will be adding some tests that will check the correctness of diagnostic wording in the subsequent commits?

[Topotuna]

In D108379#2954826, @Anastasia wrote:

LGTM! Thanks!

I imagine you will be adding some tests that will check the correctness of diagnostic wording in the subsequent commits?

Yes, I will add tests for diagnostics reporting once C++ for OpenCL 2021 achieves similar functionality as OpenCL 3.0.

[Topotuna]

Changes rG054e331d9dbd and rG37cdc7ebd9a3 contain test cases that display C++ for OpenCL version 2021 in diagnostics.

clang/lib/Basic/LangOptions.cpp

bool LangOptions::isNoBuiltinFunc(StringRef FuncName) const {
   for (unsigned i = 0, e = NoBuiltinFuncs.size(); i != e; ++i)
     if (FuncName.equals(NoBuiltinFuncs[i]))
       return true;
   return false;
 }
 
 VersionTuple LangOptions::getOpenCLVersionTuple() const {
   const int Ver = OpenCLCPlusPlus ? OpenCLCPlusPlusVersion : OpenCLVersion;
+  if (OpenCLCPlusPlus && Ver != 100)
+    return VersionTuple(Ver / 100);
   return VersionTuple(Ver / 100, (Ver % 100) / 10);
 }
 
 void LangOptions::remapPathPrefix(SmallString<256> &Path) const {
   for (const auto &Entry : MacroPrefixMap)
     if (llvm::sys::path::replace_path_prefix(Path, Entry.first, Entry.second))
       break;
 }