re PR target/28946 (assembler shifts set the flag ZF, no need to re-test to zero)

re PR target/28946 (assembler shifts set the flag ZF, no need to re-test to zero)

	PR target/28946
	* config/i386/i386.md ("*ashldi3_cconly_rex64", "*ashlsi3_cconly",
	"*ashlhi3_cconly", "*ashlqi3_cconly", "*ashrdi3_one_bit_cconly_rex64",
	"*ashrdi3_cconly_rex64", "*ashrsi3_one_bit_cconly", "*ashrsi3_cconly",
	"*ashrhi3_one_bit_cconly", "*ashrhi3_cconly",
	"*ashrqi3_one_bit_cconly", "*ashrqi3_cconly",
	"*lshrdi3_cconly_one_bit_rex64", "*lshrdi3_cconly_rex64",
	"*lshrsi3_one_bit_cconly", "*lshrsi3_cconly",
	"*lshrhi3_one_bit_cconly", "*lshrhi3_cconly",
	"*lshrqi2_one_bit_cconly", "*lshrqi2_cconly": New patterns to
	implement only CC setting effects of shift instructions.

testsuite/ChangeLog:

	PR target/28946
	* gcc.target/i386/pr28946.c: New test.

From-SVN: r117022