C Frontend updated

As I have been threatening:
(http://mail.cs.uiuc.edu/pipermail/llvmdev/2002-October/000141.html) to do
(http://mail.cs.uiuc.edu/pipermail/llvmdev/2002-September/000092.html) for
some time now, I have regenerated the X86 and Sparc C frontends. They are
now in-sync again and both emit the 'external' keyword instead of
'uninitialized' as appropriate (plus other changes).

If you are seeing stuff break, make sure you update your LLVM tree, and
make sure your llvmgcc alias is pointing to the right place (on the
research machines, the right location is:

If you have problems after making these changes, please let me know.