rs6000: Use memory_operand for all simple {l,st}*brx instructions

rs6000: Use memory_operand for all simple {l,st}*brx instructions

We run fwprop before combine, very early even in the case of fwprop1;
and fwprop1 will change memory addressing to what it considers cheaper.
After the "common" change, it now changes the indexed store instruction
in the testcase to be to a constant address.  But that is not an
improvement at all: the byte reverse instructions only exist in the
indexed form, so they will not match anymore.

This patch changes the patterns for the byte reverse instructions to
allow plain memory_operand, letting reload fix this up.

	PR target/92602
	* config/rs6000/rs6000.md (bswap<mode>2_load for HSI): Change the
	indexed_or_indirect_operand to be memory_operand.
	(bswap<mode>2_store for HSI): Ditto.
	(bswapdi2_load): Ditto.
	(bswapdi2_store): Ditto.

From-SVN: r278821