Add explicit keywords.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37839 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CFGPrinter.cpp b/lib/Analysis/CFGPrinter.cpp
index 7466666..d32481e 100644
--- a/lib/Analysis/CFGPrinter.cpp
+++ b/lib/Analysis/CFGPrinter.cpp
@@ -135,7 +135,7 @@
   struct VISIBILITY_HIDDEN CFGPrinter : public FunctionPass {
     static char ID; // Pass identification, replacement for typeid
     CFGPrinter() : FunctionPass((intptr_t)&ID) {}
-    CFGPrinter(intptr_t pid) : FunctionPass(pid) {}
+    explicit CFGPrinter(intptr_t pid) : FunctionPass(pid) {}
 
     virtual bool runOnFunction(Function &F) {
       std::string Filename = "cfg." + F.getName() + ".dot";