enabling instrumentation for stage 3 compilers

[nobellium1997]

This commit allows users to instrument their stage 3 compilers.

This PR is a revival of the following PR: #101744

The aim is to break up the PR into smaller chunks and merge these changes in piecemeal. The PR here is to allow us to instrument stage 3 rust compilers as stage 3 instrumentation is part of how we create profiles for guided optimization later on.

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[Kobzol]

Hi, could you say more about the use-case please? (the change looks simple enough though)