clang-format: Fix corner case in ObjC interface definitions.

In
  @implementation ObjcClass
  - (void)method;
  {
  }
  @end
the ObjC compiler seems to accept the superfluous comma after "method",
but clang-format used to assert on the subsequent "{".

This fixes llvm.org/PR16604.

llvm-svn: 189453

clang/lib/Format/UnwrappedLineParser.cpp

@@ -1030,7 +1030,13 @@ void UnwrappedLineParser::parseObjCUntilAtEnd() {
       addUnwrappedLine();
       break;
     }
-    parseStructuralElement();
+    if (FormatTok->is(tok::l_brace)) {
+      parseBlock(/*MustBeDeclaration=*/false);
+      // In ObjC interfaces, nothing should be following the "}".
+      addUnwrappedLine();
+    } else {
+      parseStructuralElement();
+    }
   } while (!eof());
 }