ELFYAML: Add support for parsing AMDGPU section attribute flags

[silvas]

LGTM.

lib/Object/ELFYAML.cpp

default:
     // Nothing to do.
     break;
   }
 #undef ECase
 }
 
 void ScalarBitSetTraits<ELFYAML::ELF_SHF>::bitset(IO &IO,
                                                   ELFYAML::ELF_SHF &Value) {
+  const auto *Object = static_cast<ELFYAML::Object *>(IO.getContext());
 #define BCase(X) IO.bitSetCase(Value, #X, ELF::X);
   BCase(SHF_WRITE)
   BCase(SHF_ALLOC)
   BCase(SHF_EXCLUDE)
   BCase(SHF_EXECINSTR)
   BCase(SHF_MERGE)
   BCase(SHF_STRINGS)
   BCase(SHF_INFO_LINK)
   BCase(SHF_LINK_ORDER)
   BCase(SHF_OS_NONCONFORMING)
   BCase(SHF_GROUP)
   BCase(SHF_TLS)
+  switch(Object->Header.Machine) {
+  case ELF::EM_AMDGPU:
+    BCase(SHF_AMDGPU_HSA_GLOBAL)
+    BCase(SHF_AMDGPU_HSA_READONLY)
+    BCase(SHF_AMDGPU_HSA_CODE)
+    BCase(SHF_AMDGPU_HSA_AGENT)
+    break;
+  default:
+    // Nothing to do.
+    break;
+  }
 #undef BCase
 }
 
 void ScalarEnumerationTraits<ELFYAML::ELF_STT>::enumeration(
     IO &IO, ELFYAML::ELF_STT &Value) {
 #define ECase(X) IO.enumCase(Value, #X, ELF::X);
   ECase(STT_NOTYPE)
   ECase(STT_OBJECT)

test/Object/AMDGPU/elf-definitios.yaml

 # RUN: yaml2obj -format=elf %s > %t.o
-# RUN: llvm-readobj -file-headers %t.o | FileCheck %s
+# RUN: llvm-readobj -s -file-headers %t.o | FileCheck %s
 
 # CHECK:  Machine: EM_AMDGPU (0xE0)
+# CHECK: Sections [
+# CHECK: Section {
+# CHECK: Name: .shf_amdgpu
+# CHECK: Flags [ (0xF00000)
+# CHECK: SHF_AMDGPU_HSA_AGENT (0x800000)
+# CHECK: SHF_AMDGPU_HSA_CODE (0x400000)
+# CHECK: SHF_AMDGPU_HSA_GLOBAL (0x100000)
+# CHECK: SHF_AMDGPU_HSA_READONLY (0x200000)
+# CHECK: }
 
 ---
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_REL
   Machine: EM_AMDGPU
+
+Sections:
+  - Name:  .shf_amdgpu
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_AMDGPU_HSA_GLOBAL, SHF_AMDGPU_HSA_READONLY,
+             SHF_AMDGPU_HSA_CODE, SHF_AMDGPU_HSA_AGENT]
 ...