[clang] [clang] handle fp options in __builtin_convertvector (PR #125522)

[Timm Baeder via cfe-commits]

tbaederr wrote:

> > Are fp options (already) handled in constant evaluation?
> 
> I think they are, there are tests for it in https://github.com/llvm/llvm-project/blob/main/clang/test/AST/const-fpfeatures.c and https://github.com/llvm/llvm-project/blob/main/clang/test/AST/const-fpfeatures.cpp

They don't seem to test vectors though, does `__builtin_convertvector` also handle the new fp options when evaluated at compile time?

https://github.com/llvm/llvm-project/pull/125522