[8u20] Request for approval for JDK-8036007: javac crashes when encountering an unresolvable interface

[Dan Smith]

Please approve backporting this langtools fix from 9 to 8u.  It is necessary to support backporting JDK-8034147 -- I've already completed the 8034147 backport, but didn't notice that its test fails in 8u without the 8036007 fix.

Bug report: https://bugs.openjdk.java.net/browse/JDK-8036007
Patch in jdk9: http://hg.openjdk.java.net/jdk9/dev/langtools/rev/3dd1606e93fb

—Dan