Re-target for ES.Next (#3901)

A list of changes:
- 'es2015-subset' profile is deprecated, and an 'es.next' profile is added.
- The default profile is changed to 'es.next'
- Renamed the JERRY_ES2015 guard to JERRY_ESNEXT
- Renamed JERRY_ES2015_BUILTIN_* guards to JERRY_BUILTIN_*
- Moved es2015 specific tests to a new 'es.next' subdirectory
- Updated docs, targets, and test runners to reflect these changes

Resolves #3737.

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

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

@@ -298,7 +298,7 @@ ecma_utf8_string_to_number_by_radix (const lit_utf8_byte_t *str_p, /**< utf-8 st
   JERRY_ASSERT (radix == 2 || radix == 8 || radix == 16);
   ecma_number_t num = ECMA_NUMBER_ZERO;
 
-#if ENABLED (JERRY_ES2015)
+#if ENABLED (JERRY_ESNEXT)
   if (radix <= 8)
   {
     lit_code_point_t upper_limit = LIT_CHAR_0 + radix;
@@ -321,7 +321,7 @@ ecma_utf8_string_to_number_by_radix (const lit_utf8_byte_t *str_p, /**< utf-8 st
 
     return num;
   }
-#endif /* ENABLED (JERRY_ES2015) */
+#endif /* ENABLED (JERRY_ESNEXT) */
 
   for (const lit_utf8_byte_t * iter_p = str_p; iter_p <= end_p; iter_p++)
   {