JIT: make profile data available to inlinees (#42277)

JIT: make profile data available to inlinees (#42277)

Update the jit to try and read profile data for inlinees, and if successful,
scale it appropriately for the inline call site. This kicks in for crossgen
BBOPT and TieredPGO Tier1.

Update VM and Crossgen hosts to handle requests for inlinee profile counts.
Crossgen2 does not seem to support profile data retrieval yet.

Note crossgen experience may not be as good as one might expect, because
crossgen BBINSTR loses counts for inlinees. But enabling this for crossgen
even with this limitation is probably a win overall.

Fix small issue in the jit where we were overly aggressive about merging the
callee block's flags into the callsite block's flags.