[Bug #18890] newline should be insignificant after pattern label

parse.y

@@ -7457,7 +7457,7 @@ parser_string_term(struct parser_params *p, int func)
     }
     if ((func & STR_FUNC_LABEL) && IS_LABEL_SUFFIX(0)) {
 	nextc(p);
-	SET_LEX_STATE(EXPR_BEG|EXPR_LABEL);
+	SET_LEX_STATE(EXPR_ARG|EXPR_LABELED);
 	return tLABEL_END;
     }
     SET_LEX_STATE(EXPR_END);

test/ruby/test_parse.rb

@@ -1370,6 +1370,39 @@ x = __ENCODING__
     assert_syntax_error('x = \ 42', /escaped space/)
   end
 
+  def test_label
+    expected = {:foo => 1}
+
+    code = '{"foo": 1}'
+    assert_valid_syntax(code)
+    assert_equal(expected, eval(code))
+
+    code = '{foo: 1}'
+    assert_valid_syntax(code)
+    assert_equal(expected, eval(code))
+
+    class << (obj = Object.new)
+      attr_reader :arg
+      def set(arg)
+        @arg = arg
+      end
+    end
+
+    assert_valid_syntax(code = "#{<<~"do;"}\n#{<<~'end;'}")
+    do;
+      obj.set foo:
+                1
+    end;
+    assert_equal(expected, eval(code))
+
+    assert_valid_syntax(code = "#{<<~"do;"}\n#{<<~'end;'}")
+    do;
+      obj.set "foo":
+                  1
+    end;
+    assert_equal(expected, eval(code))
+  end
+
 =begin
   def test_past_scope_variable
     assert_warning(/past scope/) {catch {|tag| eval("BEGIN{throw tag}; tap {a = 1}; a")}}

test/ruby/test_pattern_matching.rb

@@ -1155,6 +1155,21 @@ END
       end
     end
 
+    [{a: 42}, {b: 42}].each do |i|
+      assert_block('newline should be insignificant after pattern label') do
+        case i
+        in a:
+          0
+          true
+        in "b":
+          0
+          true
+        else
+          false
+        end
+      end
+    end
+
     assert_syntax_error(%q{
       case _
       in a:, a: