Eclipse Java Compiler (ECJ) used to build and support the Java frontend
of GCC, the GNU Compiler Collection.
This is not new code to us, but breaks out what we have been manually
(and redundantly) carrying in our four GCC 4.6, 4.7 and 4.8 ports
lang/gcc, lang/gcc46, lang/gcc47 and lang/gcc48.
PR: 175072
