Remove ES_NEXT macro (#4915)

- remove all '#JERRY_ESNEXT' macro
- remove 5.1 build profile, update test runner accordingly (Note: all builtins are turn on by default)
- move tests from tests/jerry/esnext into tests/jerry, concatenate files with same names
- add skiplist to some snapshot tests that were supported only in 5.1
- fix doxygen issues that were hidden before (bc. of es.next macro)

Co-authored-by: Martin Negyokru negyokru@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Adam Szilagyi aszilagy@inf.u-szeged.hu

jerry-core/ecma/base/ecma-extended-info.h

@@ -25,8 +25,6 @@
 
 #include "ecma-globals.h"
 
-#if JERRY_ESNEXT || JERRY_FUNCTION_TO_STRING
-
 /**
  * Vlq encoding: flag which is set for all bytes except the last one.
  */
@@ -48,8 +46,6 @@ uint32_t ecma_extended_info_get_encoded_length (uint32_t value);
 
 uint8_t *ecma_compiled_code_resolve_extended_info (const ecma_compiled_code_t *bytecode_header_p);
 
-#endif /* JERRY_ESNEXT || JERRY_FUNCTION_TO_STRING */
-
 /**
  * @}
  * @}