AMDGPU: Remove max_scratch_backing_memory_byte_size from kernel header

1. Remove max_scratch_backing_memory_byte_size from kernel header
2. Make it a reserved field
3. Ignore it while parsing assembly for backwards compatibility
4. Bump up minor version of kernel header

Differential Revision: https://reviews.llvm.org/D45452

llvm-svn: 329620
diff --git a/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp b/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
index 4680e5f..02efecf 100644
--- a/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
@@ -423,7 +423,7 @@
   memset(&Header, 0, sizeof(Header));
 
   Header.amd_kernel_code_version_major = 1;
-  Header.amd_kernel_code_version_minor = 1;
+  Header.amd_kernel_code_version_minor = 2;
   Header.amd_machine_kind = 1; // AMD_MACHINE_KIND_AMDGPU
   Header.amd_machine_version_major = ISA.Major;
   Header.amd_machine_version_minor = ISA.Minor;