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/ARM/ARMMachineFunctionInfo.h b/lib/Target/ARM/ARMMachineFunctionInfo.h
index 6662be1..0b0e289 100644
--- a/lib/Target/ARM/ARMMachineFunctionInfo.h
+++ b/lib/Target/ARM/ARMMachineFunctionInfo.h
@@ -100,7 +100,7 @@
     GPRCS1Frames(0), GPRCS2Frames(0), DPRCSFrames(0),
     JumpTableUId(0), ConstPoolEntryUId(0) {}
 
-  ARMFunctionInfo(MachineFunction &MF) :
+  explicit ARMFunctionInfo(MachineFunction &MF) :
     isThumb(MF.getTarget().getSubtarget<ARMSubtarget>().isThumb()),
     Align(isThumb ? 1U : 2U),
     VarArgsRegSaveSize(0), HasStackFrame(false),