Add explicit keywords, and fix a minor typo that they uncovered.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45034 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ELFWriter.cpp b/lib/CodeGen/ELFWriter.cpp
index efdf029..d054adb 100644
--- a/lib/CodeGen/ELFWriter.cpp
+++ b/lib/CodeGen/ELFWriter.cpp
@@ -72,7 +72,7 @@
     std::vector<unsigned char> *OutBuffer;
     size_t FnStart;
   public:
-    ELFCodeEmitter(ELFWriter &ew) : EW(ew), TM(EW.TM), OutBuffer(0) {}
+    explicit ELFCodeEmitter(ELFWriter &ew) : EW(ew), TM(EW.TM), OutBuffer(0) {}
 
     void startFunction(MachineFunction &F);
     bool finishFunction(MachineFunction &F);