Rollup merge of rust-lang#144974 - tgross35:update-builtins, r=tgross35

compiler-builtins subtree update

Subtree update of `compiler-builtins` to rust-lang/compiler-builtins@87a66ec.

Created using https://github.com/rust-lang/josh-sync.

r? ``@ghost``

Author: tgross35