swift234

Improve parsing of '>>?!>?' jumbles in type context.

Use the same token-splitting technique we use to interpret '>>>' as a series of closing angle brackets to also extract '?' and '!' IUO sigils. Tweak it so that we properly reset the lexer state instead of just peeking the next token, because otherwise, when we chop a token like '>?>>', we'll see only the '?' (because '?' by itself is a question_postfix) and drop the '>>' on the floor. Remove the lexer hacks that pattern-matched specific >?>? sequences.

Swift SVN r22669