Preserve `kwarg` flag and fix up f5c904c2a9

parse.y

@@ -3964,11 +3964,13 @@ p_expr_basic	: p_value
 		| tLBRACE
 		    {
 			$<tbl>$ = push_pktbl(p);
+			$<flags>1 = p->in;
 			p->in.kwarg = 0;
 		    }
 		  p_kwargs rbrace
 		    {
 			pop_pktbl(p, $<tbl>2);
+			p->in.kwarg = $<flags>1.kwarg;
 			$$ = new_hash_pattern(p, Qnone, $3, &@$);
 		    }
 		| tLBRACE rbrace

test/ruby/test_pattern_matching.rb

@@ -1060,6 +1060,8 @@ END
       in {a:
             2}
         false
+      in a: {b:}, c:
+        p c
       in {a:
       }
         _a = a