[AMDGPU] Split R600/SI getFrameIndexReference and emit stack object offsets for SI

Differential Revision: https://reviews.llvm.org/D29674


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297499 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed