Make helper functions static.

llvm-svn: 207359
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
index 84c9a88..72cab60 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
@@ -14,7 +14,7 @@
 
 MCSymbol *DwarfStringPool::getSectionSymbol() { return SectionSymbol; }
 
-std::pair<MCSymbol *, unsigned> &
+static std::pair<MCSymbol *, unsigned> &
 getEntry(AsmPrinter &Asm,
          StringMap<std::pair<MCSymbol *, unsigned>, BumpPtrAllocator &> &Pool,
          StringRef Prefix, StringRef Str) {