Implement seeking in the pre-scanner info. (#3126)

After changing the lexing position, the current
position of the scanner info must be moved as well.

Fixes #3101
Fixes #3102

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

tests/jerry/fail/regression-test-issue-3101.js

@@ -0,0 +1,17 @@
+// 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.
+
+for ( ; ; ( ) => 0) {
+    for ( ; $; $) ;
+}

tests/jerry/fail/regression-test-issue-3102.js

@@ -0,0 +1,17 @@
+// 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.
+
+while ( $(($) => {}) ) {
+    while ($);
+}

tests/jerry/prescanner.js

@@ -0,0 +1,52 @@
+// 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.
+
+var a = 0;
+var count = 0;
+while ( function() { while (++a < 0) ; } (), a < 4) {
+  while (++count < 0) ;
+}
+assert(count == 3);
+
+for (a = 0, count = 0; function() { while (++a < 0) ; } (), a < 4 ; ) {
+  while (++count < 0) ;
+}
+assert(count == 3);
+
+a = 0;
+count = 0;
+switch (100) {
+  default:
+    while (++a < 2) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 1; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 2; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 3; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 4; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+}
+
+assert (count == 14);
+assert (a == 2);