Reapply "[AMDGPU] Modify adjustInliningThreshold to also consider the cost of...

Reapply "[AMDGPU] Modify adjustInliningThreshold to also consider the cost of passing function arguments through the stack"

Reapplies 142c28ff as part of D140242 which got reverted due to amdgpu openmp test failures.

This diff fixes said failures by eliding most of `adjustInliningThresholdUsingCallee` for indirect calls as the callee function is unavailable for indirect calls.

Reviewed By: arsenm, #amdgpu

Differential Revision: https://reviews.llvm.org/D143498