Rework RegExp engine and add support for proper unicode matching (#3746)

This change includes several bugfixes, general improvements, and support
for additional features.
- Added full support for web compatibility syntax defined in Annex B
- Implemented parsing and matching patterns in unicode mode
- Fixed capture results when iterating with nested capturing groups
- Significantly reduced regexp bytecode size
- Reduced stack usage during regexp execution
- Improved matching performance

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai dbatyai@inf.u-szeged.hu

jerry-core/ecma/base/ecma-helpers-string.c

@@ -2362,8 +2362,7 @@ ecma_string_trim_helper (const lit_utf8_byte_t **utf8_str_p, /**< [in, out] curr
   {
     read_size = lit_read_code_unit_from_utf8 (current_p, &ch);
 
-    if (!lit_char_is_white_space (ch)
-        && !lit_char_is_line_terminator (ch))
+    if (!lit_char_is_white_space (ch))
     {
       nonws_start_p = current_p;
       break;
@@ -2378,8 +2377,7 @@ ecma_string_trim_helper (const lit_utf8_byte_t **utf8_str_p, /**< [in, out] curr
   {
     read_size = lit_read_prev_code_unit_from_utf8 (current_p, &ch);
 
-    if (!lit_char_is_white_space (ch)
-        && !lit_char_is_line_terminator (ch))
+    if (!lit_char_is_white_space (ch))
     {
       break;
     }