Support for Javascript Generator functions

[AdamantLife]

Issue

Javascript Generator Functions raise Syntax Error by the parser

Environment

Python 3.10 inside fresh venv virtual environment on Windows 10
slimit installed via a requirements.txt, using git+https://github.com/rspivak/slimit.git#egg=slimit

MVE

# test.py
import slimit
slimit.minify("function* test(){yield 1;}")

Traceback

Traceback (most recent call last):
  File "[...]\test.py", line 2, in <module>
    slimit.minify("function* test(){yield 1;}")
  File "[...]\lib\site-packages\slimit\minifier.py", line 38, in minify
    tree = parser.parse(text)
  File "[...]\lib\site-packages\slimit\parser.py", line 93, in parse
    return self.parser.parse(text, lexer=self.lexer, debug=debug)
  File "[...]\lib\site-packages\ply\yacc.py", line 333, in parse
    return self.parseopt_notrack(input, lexer, debug, tracking, tokenfunc)
  File "[...]\lib\site-packages\ply\yacc.py", line 1201, in parseopt_notrack
    tok = call_errorfunc(self.errorfunc, errtoken, self)
  File "[...]\lib\site-packages\ply\yacc.py", line 192, in call_errorfunc
    r = errorfunc(token)
  File "[...]lib\site-packages\slimit\parser.py", line 116, in p_error
    self._raise_syntax_error(token)
  File "[...]\lib\site-packages\slimit\parser.py", line 86, in _raise_syntax_error
    raise SyntaxError(
SyntaxError: Unexpected token (MULT, '*') at 1:9 between LexToken(FUNCTION,'function',1,1) and LexToken(ID,'test',1,11)