RFR(L): 8005071: Incremental inlining for JSR 292

[Roland Westrelin]

Here is a new webrev:

http://cr.openjdk.java.net/~roland/8005031/webrev.01/

- I dropped the special purpose dead code elimination, made stricter checks of inputs when inlining incrementally, and now do one igvn for every successful inlining

- I made a couple fixes to PhaseStringOpts so it works ok when it happens after all inlining

- I took all suggestions that Vladimir and Christian made into account

Roland.