This patch adds a build phase to GCJ removing a broken symlink and a
couple of non-functional binaries, such as "gcc" or "g++".

In a GCJ build these binaries are useless as GCJ is a GCC built only
with Java support.  When GCJ is installed alongside gcc-toolchain, for
example, there would be conflicts with GCJ's "gcc" stump binary
shadowing the usable "gcc" binary from gcc-toolchain.

Removing these binaries should be harmless as users of GCJ are unlikely
to use "gcc" but "gcj" directly.