[AMDGPU] Restructure code object metadata creation
  - Rename runtime metadata -> code object metadata
  - Make metadata not flow
  - Switch enums to use ScalarEnumerationTraits
  - Cleanup and move AMDGPUCodeObjectMetadata.h to AMDGPU/MCTargetDesc
  - Introduce in-memory representation for attributes
  - Code object metadata streamer
  - Create metadata for isa and printf during EmitStartOfAsmFile
  - Create metadata for kernel during EmitFunctionBodyStart
  - Finalize and emit metadata to .note during EmitEndOfAsmFile
  - Other minor improvements/bug fixes

Differential Revision: https://reviews.llvm.org/D29948



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298552 91177308-0d34-0410-b5e6-96231b3b80d8
32 files changed