AArch64: Improve immediate expansion [PR105928]

AArch64: Improve immediate expansion [PR105928]

Support immediate expansion of immediates which can be created from 2 MOVKs
and a shifted ORR or BIC instruction.  Change aarch64_split_dimode_const_store
to apply if we save one instruction.

This reduces the number of 4-instruction immediates in SPECINT/FP by 5%.

gcc/ChangeLog:
	PR target/105928
	* config/aarch64/aarch64.cc (aarch64_internal_mov_immediate)
	Add support for immediates using shifted ORR/BIC.
	(aarch64_split_dimode_const_store): Apply if we save one instruction.
	* config/aarch64/aarch64.md (<LOGICAL:optab>_<SHIFT:optab><mode>3):
	Make pattern global.

gcc/testsuite:
	PR target/105928
	* gcc.target/aarch64/pr105928.c: Add new test.
	* gcc.target/aarch64/vect-cse-codegen.c: Fix test.