[PATCH 1/2] ia64: Fix zero_call_used_regs for PRs [PR121535]

[PATCH 1/2] ia64: Fix zero_call_used_regs for PRs [PR121535]

ia64 uses default_zero_call_used_regs(), which uses emit_move_insn()
to zero out registers. ia64 predicate registers use BImode, which is not
supported by emit_move_insn().

Implement ia64_zero_call_used_regs() to zero PRs by manually emitting
a CCImode move. default_zero_call_used_regs() is then called to handle
the remaining registers.

	PR target/121535

gcc/ChangeLog:

	* config/ia64/ia64.cc (TARGET_ZERO_CALL_USED_REGS): Override
	function with target-specific one.
	(struct gcc_target): Move to end of file.
	(ia64_zero_call_used_regs): Add target-specific function.

gcc/testsuite/ChangeLog:

	* gcc.target/ia64/pr121535.c: New test.

Signed-off-by: Tomas Glozar <tglozar@gmail.com>