Remove a dead diagnostic, NFC

This was issued in Objective-C 1 mode, but we not longer support that, so this
is just unreachable.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@367708 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/DiagnosticParseKinds.td

@@ -436,8 +436,6 @@ def err_objc_property_requires_field_name : Error<
   "property requires fields to be named">;
 def err_objc_property_bitfield : Error<"property name cannot be a bit-field">;
 def err_objc_expected_property_attr : Error<"unknown property attribute %0">;
-def err_objc_properties_require_objc2 : Error<
-  "properties are an Objective-C 2 feature">;
 def err_objc_unexpected_attr : Error<
   "prefix attribute must be followed by an interface, protocol, or implementation">;
 def err_objc_postfix_attribute : Error <

lib/Parse/ParseObjc.cpp

@@ -710,7 +710,6 @@ void Parser::ParseObjCInterfaceDeclList(tok::ObjCKeywordKind contextKey,
     case tok::objc_required:
     case tok::objc_optional:
       // This is only valid on protocols.
-      // FIXME: Should this check for ObjC2 being enabled?
       if (contextKey != tok::objc_protocol)
         Diag(AtLoc, diag::err_objc_directive_only_in_protocol);
       else
@@ -718,9 +717,6 @@ void Parser::ParseObjCInterfaceDeclList(tok::ObjCKeywordKind contextKey,
       break;
 
     case tok::objc_property:
-      if (!getLangOpts().ObjC)
-        Diag(AtLoc, diag::err_objc_properties_require_objc2);
-
       ObjCDeclSpec OCDS;
       SourceLocation LParenLoc;
       // Parse property attribute list, if any.