Escape analysis can't trace flows through recursive functions

[edwardwawrzynek]

Right now, if the escape analyzer finds a call to a function currently being analyzed, it assumes all arguments escape in that call.

Some cases are easy to resolve, but many aren't:

• Recursive functions which switch arguments around -- ie func(a, b) calls func(b, a)
• Functions with argument->argument flows
• Complex mutually recursive functions

Solutions:
Assume no arguments escape from the call, produce function flows, rerun analysis with those flows. Repeat until resulting flows stabilize.

This has major drawbacks:

• Analysis has to be rerun multiple times.
• Flows may never stabilize?