[llvm-objdump] Add the missing ARMv8 subarch detection

Differential Revision: https://reviews.llvm.org/D66849

llvm-svn: 370163
diff --git a/llvm/lib/Object/ELFObjectFile.cpp b/llvm/lib/Object/ELFObjectFile.cpp
index 82e9b89..a10c643 100644
--- a/llvm/lib/Object/ELFObjectFile.cpp
+++ b/llvm/lib/Object/ELFObjectFile.cpp
@@ -356,6 +356,21 @@
     case ARMBuildAttrs::v7E_M:
       Triple += "v7em";
       break;
+    case ARMBuildAttrs::v8_A:
+      Triple += "v8a";
+      break;
+    case ARMBuildAttrs::v8_R:
+      Triple += "v8r";
+      break;
+    case ARMBuildAttrs::v8_M_Base:
+      Triple += "v8m.base";
+      break;
+    case ARMBuildAttrs::v8_M_Main:
+      Triple += "v8m.main";
+      break;
+    case ARMBuildAttrs::v8_1_M_Main:
+      Triple += "v8.1m.main";
+      break;
     }
   }
   if (!isLittleEndian())