This change was triggered by BZ #247974 which suggested to include
VEX/test_main.* in the tarball. We don't want to do that because those
files are really just scaffolding for developers to play with and not
meant for general consumption (and are also bitrotting ATM). Therefore,
this patch moves them to the "useful" subdirectory and adds a crude
Makefile there to build the executable.
Makefile-gcc updated accordingly.


git-svn-id: svn://svn.valgrind.org/vex@2998 8f6e269a-dfd6-0310-a8e1-e2731360e62c