RFR(XL): 6312651: Compiler should only use verified interface types for optimization

[Roland Westrelin]

Hi Vladimir,

> I believe the culprit here is that I observe the failures on MacOS only. 
> I have no idea why it doesn't show up on Linux.

Indeed, I can reproduce it on macos. The issue is some of the code I
added rely on evaluation ordering of arguments to some method and that
differs with llvm.

Anyway, here is a new webrev that should fix all failures you
encountered and rebased to current jdk/jdk:

http://cr.openjdk.java.net/~roland/6312651/webrev.01/

Roland.