[12] RFR(S) 8206963: [AOT] bug with multiple class loaders

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/8206963/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8206963

After investigations and discussions I suggest that AOT should not support custom class loaders. The main issue is 
during AOT compilation we don't know anything about them and their constrains. JAOTC uses only standard builtin loaders.
Otherwise we would have to add class runtime checks to all field accesses and inlined code and create separate memory 
for class pointers (AOT 'got' cells) per method which may cause significant performance regression.

I will update limitations in AOT JEP.

Changes passed tier1-3 and Xcomp testing.

-- 
Thanks,
Vladimir