[PowerPC] check for INLINEASM_BR along w/ INLINEASM

Summary:
It looks like since INLINEASM_BR was created off of INLINEASM (r353563),
a few checks for INLINEASM needed to be updated to check for either
case.

pr/41999

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: nemanjai, hiraditya, kbarton, jsji, llvm-commits, craig.topper, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62403

llvm-svn: 362278