[8u-60] request for review and approval to backport JDK-8080842: Using Lambda Expression with name clash results in ClassFormatError

[Jan Lahoda]

Hello,

I'd like to ask for a code review and an approval to backport the 
following fix to 8u-dev:

Bug: https://bugs.openjdk.java.net/browse/JDK-8080842
jdk9 fix: http://hg.openjdk.java.net/jdk9/dev/langtools/rev/283c9951fd23

The fix does not apply cleanly to 8u-dev/langtools. The webrev for 
8u-dev is here:
http://cr.openjdk.java.net/~jlahoda/8080842-8/webrev.00/

Notable changes between the jdk9 and 8u-dev fixes:
-in Scope, using an anonymous innerclass instead of a lambda for filter
-in RemoveSymbolUnitTest.java, several changes to adjust to Scope as it 
was in 8 (WriteableScope.create -> new Scope; Scope.findFirst -> 
Scope.lookup(...).sym).

Thanks,
     Jan