Parser: Avoid a crash-on-invalid when trying to diagnose function calls with -> in it.

Use the existing convenience function.

llvm-svn: 192347
diff --git a/clang/test/Parser/cxx-decl.cpp b/clang/test/Parser/cxx-decl.cpp
index c33a8d5..ea20354 100644
--- a/clang/test/Parser/cxx-decl.cpp
+++ b/clang/test/Parser/cxx-decl.cpp
@@ -202,6 +202,12 @@
   // Comment!
 }
 
+void test8() {
+  struct {} o;
+  // This used to crash.
+  (&o)->(); // expected-error{{expected unqualified-id}}
+}
+
 namespace PR5066 {
   template<typename T> struct X {};
   X<int N> x; // expected-error {{type-id cannot have a name}}