swift

f4176300 - Add option to reduce build times when using ThinLTO and ld64 (#41058)

Add option to reduce build times when using ThinLTO and ld64 (#41058) Internal configurations targeting Darwin employ ThinLTO to improve compiler performance, however using it on all executable causes build time to increase with no matching benefit. To reduce build times in such configurations, we allow some ancillary targets to opt out of LLVM IR optimizations when linking ThinLTO with ld64 (e.g. tools used for bootstrapping or debugging the Swift compiler) -- this behaviour is opt in through a new flag `--swift-tools-ld64-lto-codegen-only-for-supporting-targets`. Addresses rdar://76702687