Fix subtle bug introduced in r54852.

- UsualUnaryConversions takes an Expr *& and may modify its argument,
   this broke when it was refactored into Sema::CheckCastTypes. This
   meant that we were missing implicit casts in some places.
 - Seems pretty sad that this got through our tests.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55039 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/Sema.h

@@ -871,7 +871,7 @@ private:
   bool CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT);
 
   /// CheckCastTypes - Check type constraints for casting between types.
-  bool CheckCastTypes(SourceRange TyRange, QualType CastTy, Expr *CastExpr);
+  bool CheckCastTypes(SourceRange TyRange, QualType CastTy, Expr *&CastExpr);
   
   // CheckVectorCast - check type constraints for vectors. 
   // Since vectors are an extension, there are no C standard reference for this.

lib/Sema/SemaExpr.cpp

@@ -1089,7 +1089,7 @@ ActOnInitList(SourceLocation LBraceLoc, ExprTy **initlist, unsigned NumInit,
 }
 
 /// CheckCastTypes - Check type constraints for casting between types.
-bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *castExpr) {
+bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr) {
   UsualUnaryConversions(castExpr);
 
   // C99 6.5.4p2: the cast type needs to be void or scalar and the expression

test/CodeGen/2008-08-19-cast-of-typedef.c

@@ -0,0 +1,10 @@
+// RUN: clang --emit-llvm -o %t %s
+
+typedef short T[4];
+struct s {
+  T f0;
+};
+
+void foo(struct s *x) {
+  bar((long) x->f0);
+}