[CIR] Upstream CIR codegen for mxcsr x86 builtins#167948

Thibault-Monnier wants to merge 4 commits intollvm:mainllvm/llvm-project:mainfrom

Thibault-Monnier:cir-mxcsr-codegenThibault-Monnier/llvm-project:cir-mxcsr-codegenCopy head branch name to clipboard