This is a rework of:

        http://sources.redhat.com/ml/gdb-patches/2005-05/msg00405.html

Hopefully this patch will be more acceptable.

2005-05-17  Joel Brobecker  <brobecker@adacore.com>

        * alpha-tdep.c (fp_register_zero_p): New function.
        (fp_register_sign_bit): New function.
        (alpha_next_pc): Add support for floating-point control instructions.

Tested on alpha-tru64 5.1a with no regression. I'll try to contribute
an asm test asap.

One remark: For zero_mask in fp_register_zero_p(), Richard suggested
to use "((LONGEST) 1 << 63) - 1", but that triggered an overflow warning
from GCC. So I reverted to using the xor binary operator. Daniel said
that many things would break in GDB with 128-bit types, so I think the
xor is quite acceptable for now.

OK to commit?

Thanks,
-- 
Joel