Rollup merge of #71364 - Amanieu:zprofile_compiler_builtins, r=cramertj
Rollup merge of #71364 - Amanieu:zprofile_compiler_builtins, r=cramertj

Ignore -Zprofile when building compiler_builtins

#70846 made the `compiler_builtins` crate ignore the default codegen-units setting and instead always split each function into a different codegen unit.

This unfortunately breaks `-Zprofile` which requires a single codegen unit per crate (see #71283). You can notice this when building with `cargo -Zbuild-std` and `RUSTFLAGS` containing `-Zprofile`.

This PR works around this issue by just ignoring `-Zprofile` for the `compiler-builtins` crate.

aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust