Add explicit keywords.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72969 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Alpha/AlphaMachineFunctionInfo.h b/lib/Target/Alpha/AlphaMachineFunctionInfo.h
index 47de5df..8221fc7 100644
--- a/lib/Target/Alpha/AlphaMachineFunctionInfo.h
+++ b/lib/Target/Alpha/AlphaMachineFunctionInfo.h
@@ -33,8 +33,8 @@
 public:
   AlphaMachineFunctionInfo() : GlobalBaseReg(0), GlobalRetAddr(0) {}
 
-  AlphaMachineFunctionInfo(MachineFunction &MF) : GlobalBaseReg(0),
-                                                  GlobalRetAddr(0) {}
+  explicit AlphaMachineFunctionInfo(MachineFunction &MF) : GlobalBaseReg(0),
+                                                           GlobalRetAddr(0) {}
 
   unsigned getGlobalBaseReg() const { return GlobalBaseReg; }
   void setGlobalBaseReg(unsigned Reg) { GlobalBaseReg = Reg; }