[compiler-rt] Add NewPM testing to CFI tests

Summary:
Executes both LTO and ThinLTO CFI tests an additional time using the new
pass manager. I only bothered to add with gold and not lld as testing
with one linker should be sufficient. I didn't add for APPLE or WIN32
since I don't have a way to test those.

Depends on D49429.

Reviewers: pcc

Subscribers: dberris, mgorny, mehdi_amini, delcypher, dexonsmith, #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D49432

llvm-svn: 337465