Use CastExpr::CK_ArrayToPointerDecay and fix an assert.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78502 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaExprCXX.cpp

@@ -927,7 +927,7 @@ Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
 
   case ICK_Array_To_Pointer:
     FromType = Context.getArrayDecayedType(FromType);
-    ImpCastExprToType(From, FromType);
+    ImpCastExprToType(From, FromType, CastExpr::CK_ArrayToPointerDecay);
     break;
 
   case ICK_Function_To_Pointer:

test/CodeGenCXX/array-pointer-decay.cpp

@@ -0,0 +1,7 @@
+// RUN: clang-cc %s -emit-llvm -o -
+
+void f(const char*);
+
+void g() {
+  f("hello");
+}