[7u85] Request for Approval: 7157798: Add 6 test scenarios for testing inheritance of multiple same-name methods from mulitple interfaces

[Konstantin Shefov]

Hello

Please approve direct backport of regression tests from JDK8u to JDK 7u:
Changeset for JDK 8u: 
http://hg.openjdk.java.net/jdk8u/jdk8u-dev/langtools/rev/f5dbd6895994

Tests pass successfully against JDK 7u85 without any changes.

This backport should have been done long ago but for some reasons it has 
not been done.

Thanks
-Konstantin