`Unterminated regular expression` for valid code containing division

[fdietze]

acorn@5.7.2

$ echo 'f(a/b,a/b,a.of/b)' | acorn --ecma6
Unterminated regular expression (1:15)

The slashes are division, not a regular expression.

ecma3 to ecma5 work well, while from ecma6 the error occurs.

[marijnh]

That was an issue in the tokenizer. Attached patch should resolve it.