[AMDGPU] Don't constrain callees with inlinehint from inlining on MaxBB check

[AMDGPU] Don't constrain callees with inlinehint from inlining on MaxBB check

Summary: Function bodies marked inline in an opencl source are eliminated but MaxBB check may prevent inlining them leaving undefined references.

Reviewers: rampitec, arsenm

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, Anastasia, t-tye, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63337

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363418 91177308-0d34-0410-b5e6-96231b3b80d8