re PR target/25554 (unrecognizable insn on x86_64 with -O2 -ftracer ( -fno-tree-dominator-opts on the mainline))

	PR target/25554
	* config/i386/i386.md (testqi_ext_3): Ensure len is positive
	and pos non-negative and pos + len <= 32.
	(testqi_ext_3_rex64): Ensure len is positive and pos non-negative,
	drop pos + len < HOST_BITS_PER_WIDE_INT test.
	(testqi_ext_3* splitter): Handle pos + len == HOST_BITS_PER_WIDE_INT.

	* gcc.c-torture/compile/20051228-1.c: New test.

From-SVN: r109317