rs6000: use lis;xoris to build constant

rs6000: use lis;xoris to build constant

For constant C:
If '(c & 0xFFFFFFFF0000FFFFULL) == 0xFFFFFFFF00000000' or say:
32(1) || 1(0) || 15(x) || 16(0), we could use "lis; xoris" to build.

Here N(M) means N continuous bit M, x for M means it is ok for either
1 or 0; '||' means concatenation.

This patch update rs6000_emit_set_long_const to support those constants.

Compare with previous version:
https://gcc.gnu.org/pipermail/gcc-patches/2022-December/608292.html
This patch updates test function names only.

Bootstrap and regtest pass on ppc64{,le}.

	PR target/106708

gcc/ChangeLog:

	* config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Support building
	constants through "lis; xoris".

gcc/testsuite/ChangeLog:

	* gcc.target/powerpc/pr106708.c: Add test function.