process bounds expressions for parameters with all the parameters available

[dtarditi]

Bounds expressions need to processed during clang's semantic checking/processing phase in a scope with all the parameters available. I am about to submit a pull request where they are being processed in a scope that contains only the parameters seen so far.

This is a little complicated to implement in clang's semantic checking/processing phase. You have to delay parsing of the bounds expressions because parsing and semantic processing are intermixed.

[dtarditi]

This work is complete.