[memprof] Support installation of memprof headers

This change allows users manually calling memprof public C API (e.g. __memprof_profile_dump).

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D136067

GitOrigin-RevId: 30f6f2c09d6f663c8d098a2791cfd3201f728ba9
1 file changed