[rtl, delay-slot] Fix overload of "unchanging" bit

[Richard Henderson <rth at redhat dot com>]

As found by a c6x build failure, INSN_ANNULLED_BRANCH_P and RTL_CONST_CALL_P
both resolve to the same bit for CALL_INSNs.  I want to fix this by
restricting INSN_ANNULLED_BRANCH_P to JUMP_INSNs, since annulling the slots
for a call or a plain insn doesn't really make sense.

The following has passed stage2-gcc on sparc64-linux host (full build still
in progress), with --enable-checking=yes,rtl.  It surely needs more than that,
and I'm asking for help from the relevant maintainers to give this a try.


r~

Attachment: z
Description: Text document