These are all simple pointer wrappers. Pass them by value.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178247 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/CanonicalType.h

@@ -353,7 +353,7 @@ namespace llvm {
 template<typename T>
 struct simplify_type< ::clang::CanQual<T> > {
   typedef const T *SimpleType;
-  static SimpleType getSimplifiedValue(::clang::CanQual<T> &Val) {
+  static SimpleType getSimplifiedValue(::clang::CanQual<T> Val) {
     return Val.getTypePtr();
   }
 };

include/clang/AST/Type.h

@@ -1000,7 +1000,7 @@ namespace llvm {
 /// to a specific Type class.
 template<> struct simplify_type< ::clang::QualType> {
   typedef const ::clang::Type *SimpleType;
-  static SimpleType getSimplifiedValue(::clang::QualType &Val) {
+  static SimpleType getSimplifiedValue(::clang::QualType Val) {
     return Val.getTypePtr();
   }
 };

include/clang/Analysis/CFG.h

@@ -843,7 +843,7 @@ namespace llvm {
 /// CFGTerminator to a specific Stmt class.
 template <> struct simplify_type< ::clang::CFGTerminator> {
   typedef ::clang::Stmt *SimpleType;
-  static SimpleType getSimplifiedValue(::clang::CFGTerminator &Val) {
+  static SimpleType getSimplifiedValue(::clang::CFGTerminator Val) {
     return Val.getStmt();
   }
 };

include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h

@@ -1042,7 +1042,7 @@ namespace llvm {
     typedef const T *SimpleType;
 
     static SimpleType
-    getSimplifiedValue(clang::ento::CallEventRef<T>& Val) {
+    getSimplifiedValue(clang::ento::CallEventRef<T> Val) {
       return Val.getPtr();
     }
   };