Object/RelocVisitor: Add minimal support, R_MIPS_32, for mips.

It fixes llvm-dwarfdump for mips and mipsel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173567 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Object/ELF.h

@@ -2345,6 +2345,8 @@ StringRef ELFObjectFile<ELFT>::getFileFormatName() const {
       return "ELF32-arm";
     case ELF::EM_HEXAGON:
       return "ELF32-hexagon";
+    case ELF::EM_MIPS:
+      return "ELF32-mips";
     default:
       return "ELF32-unknown";
     }