Add explicit keywords.

llvm-svn: 48801
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.h b/llvm/lib/Target/Mips/MipsInstrInfo.h
index a186f2c..9842414 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.h
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.h
@@ -46,7 +46,7 @@
   MipsTargetMachine &TM;
   const MipsRegisterInfo RI;
 public:
-  MipsInstrInfo(MipsTargetMachine &TM);
+  explicit MipsInstrInfo(MipsTargetMachine &TM);
 
   /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
   /// such, whenever a client has an instance of instruction info, it should