Parts:
* Rename ecma_string_to_utf8_string() to ecma_string_copy_to_utf8_buffer.
* Introduce ecma_string_to_utf8_bytes(), which wraps the usual 'function call-assertion' pair,
and check strict equality of size of the string and the buffer.
JerryScript-DCO-1.0-Signed-off-by: Zsolt Borbély [email protected]