[Offload][OpenMP] remove SourceInfo::removePath (#226586)

This Pr is the same as https://github.com/llvm/llvm-project/pull/226283
(which was reverted in https://github.com/llvm/llvm-project/pull/226557)
This Pr is the same as https://github.com/llvm/llvm-project/pull/226283
but with an update to info.c to account for the new full path output.

GitOrigin-RevId: 91d0e2e91e2dc4c4729cbe911f67388453ee509d