Fix Date.parse() in ecma-builtin-date.c (#2081)

Fixes issue #2073, which introduced an error caused by Date.parse()
The problem was that the function didn't properly check if there was a ':' after the hours.
If any UTF8 character was inserted there which got decoded into multiple characters, it caused the pointer to point at a wrong character.

JerryScript-DCO-1.0-Signed-off-by: Daniel Balla dballa@inf.u-szeged.hu

tests/jerry/regression-test-issue-2073.js

@@ -0,0 +1,15 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+Date.parse("2015-01-01T01߄'a': 1}:01F");