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-gc.c

@@ -1467,7 +1467,7 @@ ecma_gc_run (void)
 
 #if ENABLED (JERRY_BUILTIN_REGEXP)
   /* Free RegExp bytecodes stored in cache */
-  re_cache_gc_run ();
+  re_cache_gc ();
 #endif /* ENABLED (JERRY_BUILTIN_REGEXP) */
 } /* ecma_gc_run */