LoongArch: Optimize AND large immediate operation

LoongArch: Optimize AND large immediate operation

For large immediate values in variable AND operations:
if their bit representation has two consecutive 0 sequences,
one starting from the MSB can use the bstrpick.d instruction,
and the bstrins.d instruction for the other.

For example, in the case 'var & 0x3fffffffefffffff':

Before:
    lu12i.w $r12,-65537
    ori	    $r12,$r12,4095
    lu52i.d $r12,$r12,0x3ff
    and	    $r4,$r4,$r12

After:
    bstrpick.d	$r4,$r4,61,0
    bstrins.d	$r4,$r0,28,28

gcc/ChangeLog:

	* config/loongarch/loongarch-protos.h
	(loongarch_use_bstrins_bstrpick_for_and): New proto.
	* config/loongarch/loongarch.cc
	(loongarch_use_bstrins_bstrpick_for_and): Decide whether
	to optimize.
	(loongarch_rtx_costs): Adjust the cost of AND operation.
	* config/loongarch/loongarch.md
	(bstrins_bstrpick_for_and_imm<mode>): New insn_and_split.

gcc/testsuite/ChangeLog:

	* gcc.target/loongarch/and-large-immediate-opt.c: New test.