Make helper functions static. NFC.

Found by -Wmissing-prototypes.

llvm-svn: 231668
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 083572b..280ba57 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -1406,7 +1406,7 @@
   return true;
 }
 
-const ValueDecl *GetLValueBaseDecl(const LValue &LVal) {
+static const ValueDecl *GetLValueBaseDecl(const LValue &LVal) {
   return LVal.Base.dyn_cast<const ValueDecl*>();
 }
 
@@ -2502,8 +2502,9 @@
 }
 
 /// Find the complete object to which an LValue refers.
-CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E, AccessKinds AK,
-                                  const LValue &LVal, QualType LValType) {
+static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
+                                         AccessKinds AK, const LValue &LVal,
+                                         QualType LValType) {
   if (!LVal.Base) {
     Info.Diag(E, diag::note_constexpr_access_null) << AK;
     return CompleteObject();