[8] RFR (XS): 8036100: Default method returns true for a while, and then returns false

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8036100/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8036100

CHA still doesn't handle default methods right.

For the following hierarchy and C1 as a context:
interface I1            { default m() {} }
interface I2 extends I1 { default m() {} }

class C1            implements I1 {}
class C2 extends C1 implements I2 {}

CHA reports I1.m as a unique method. However C2.m resolves to I2.m.

The fix for 8 is to disable CHA for default methods.
Proper fix will go into 8u and 9.

It is enough to add the check on root_m, because root_m should be 
non-abstract (see ciMethod::resolve_invoke). So, it's either (1) a 
default or (2) an instance method. (1) is covered by the fix and (2) 
isn't affected by default methods, because concrete method always hides 
all default methods in the hierarchy.

Testing: regression test, vm.quick.testlist, vm.adhoc test set

Best regards,
Vladimir Ivanov