RFR: 8043275 Interface initialization for default methods

[Karen Kinnear]

Please review for 9 (8u40 back port will follow):

webrev: http://cr.openjdk.java.net/~acorn/8043275/webrev/
bug: https://bugs.openjdk.java.net/browse/JDK-8043275

Summary:
  Fix superinterface initialization to be based on declaring a non-static instance method rather than on declaring or inheriting one

Tested (linux-x64):
defmeth - enhanced
jtreg TestInterfaceInit and TestInterfaceOrder
jtreg hotspot, jdk.lambda, java.util, java.lang
jck vm, lang
nsk: vm.defmeth (added 2 tests), vm.mlvm, vm.fast.quick

Thanks to Dan Smith, Alex Buckley, John Rose for specification clarification.

thanks,
Karen