EA spends most time in Connection Graph construction which is done
during each method compilation (with EA is on) since only after CG built
we can look for scalar replaceable candidates and create unique types
for fields instances or skip it if there are no such candidates.
The Connection Graph construction should be as fast as posible.
1. I am using this push to switch on Escape Analysis by default.
2. Build Connection Graph and execute Escape Analysis only
when Ideal graph has allocations and/or locks.
Use Compile::_macro_nodes worklist check for that.
3. Several accessors methods were optimized due to the fact that
no new ideal nodes should be created during Connection Graph build.
4. Removed experimental code in oopMap.
Note: I did experiments with growableArray optimizations and they
bring nothing to the current EA code performance.
I filed separate bug to investigate gA optimizations.