Patch to enable libgcj.dll for MinGW

[Andrew Haley]

TJ Laurenzo writes:

 > Could one of you provide some guidance on the preferred way to do
 > this?  gjavah.c is part of the bootstrap sequence.  When
 > bootstrapping, the build treats any warnings as errors, so we can't
 > have any unused functions.  My original patch which removed all of
 > this stuff built properly because everything was removed.  However,
 > if I just do an #ifdef ... around some of the code we are going to
 > have at least one unused function and thus a compile error during
 > bootstrap.  I could obviously put the same ifdef in multiple
 > places, but that gets ugly.  Should I break the check out into a
 > function "int is_not_pe_coff()" and use that in a normal if
 > statement to isolate the behavior in question?

Oh dear, I am *really* sorry that making this change is causing so
much trouble!  Thanks for your patience.

ATTRIBUTE_UNUSED does the job, and you'll find examples of its use in
gcc sources.

Andrew.