Make some helpers static or move into the llvm namespace.

llvm-svn: 217077
diff --git a/llvm/lib/ProfileData/CoverageMappingWriter.cpp b/llvm/lib/ProfileData/CoverageMappingWriter.cpp
index f5e6ab4..15d3cd3 100644
--- a/llvm/lib/ProfileData/CoverageMappingWriter.cpp
+++ b/llvm/lib/ProfileData/CoverageMappingWriter.cpp
@@ -103,7 +103,8 @@
 ///     A counter with kind Counter::Expression and an expression
 ///     with kind CounterExpression::Add
 /// Remaining bits - Counter/Expression ID.
-unsigned encodeCounter(ArrayRef<CounterExpression> Expressions, Counter C) {
+static unsigned encodeCounter(ArrayRef<CounterExpression> Expressions,
+                              Counter C) {
   unsigned Tag = unsigned(C.getKind());
   if (C.isExpression())
     Tag += Expressions[C.getExpressionID()].Kind;