Include '!=' in the count of bangs in proc-macro-nested
Include '!=' in the count of bangs in proc-macro-nested

The count performed via macro_rules by proc-macro-nested needs to line
up with the count performed by proc-macro-hack via procedural macro in
order for nested macro invocations to work. The procedural macro side
simply counts Punct('!') tokens without regard for jointness. The '!='
token is the only multi-byte single macro_rules token containing '!', so
simply include it in the proc-macro-nested count as well.

dtolnay/proc-macro-hack