Enable LRA for ia64

Enable LRA for ia64

This was tested by bootstrapping GCC natively on ia64-t2-linux-gnu and
running the testsuite (based on
236116068151bbc72aaaf53d0f223fe06f7e3bac):

https://gcc.gnu.org/pipermail/gcc-testresults/2024-June/817268.html

For comparison, the same with just
236116068151bbc72aaaf53d0f223fe06f7e3bac:

https://gcc.gnu.org/pipermail/gcc-testresults/2024-June/817267.html

gcc/
	* config/ia64/ia64.cc: Enable LRA for ia64.
	* config/ia64/ia64.md: Likewise.
	* config/ia64/predicates.md: Likewise.

Signed-off-by: René Rebe <rene@exactcode.de>