[clang] [llvm] [RISCV] RISCV vector calling convention (1/2) (PR #77560)

[Shao-Ce SUN via cfe-commits]

sunshaoce wrote:

I tried compiling it and then got two warnings.
```
llvm-project/clang/lib/CodeGen/CGDebugInfo.cpp:1408:11: warning: enumeration value 'CC_RISCVVectorCall' not handled in switch [-Wswitch]
 1408 |   switch (CC) {
      |           ^~
1 warning generated.
[3629/3776] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXType.cpp.o
llvm-project/clang/tools/libclang/CXType.cpp:662:13: warning: enumeration value 'CC_RISCVVectorCall' not handled in switch [-Wswitch]
  662 |     switch (FD->getCallConv()) {
      |             ^~~~~~~~~~~~~~~~~
1 warning generated.
```

https://github.com/llvm/llvm-project/pull/77560