swift234

[EscapeAnalysis] change the invalidation+update strategy.

Get rid of the UpdateEscapeAnalysis pass and recompute the escape information on demand.
If a function is invalidated also invalidate the escape information of the function's callers .
To limit compile time, the on-demand recomputation is only done for a limited call-graph depth.
This should not be a problem because the pass manager now iterates functions in bottom-up order.