Gcc bugs break java/jdk15 build? [Workaround]

[Ken Yamada]

  FYI.

  GCC 4.2.1 alone did not solve the compilation problem on -current, but with -fno-tree-vrp compilation went without any problem.

  I added -fno-tree-vrp to CFLAGS in /etc/make.conf, and jdk15/jdk16 compilationwent successfull.