GCN, RDNA 3: Adjust 'sync_compare_and_swap<mode>_lds_insn'

For OpenACC/GCN '-march=gfx1100', a lot of libgomp OpenACC test cases FAIL:

    /tmp/ccGfLJ8a.mkoffload.2.s:406:2: error: instruction not supported on this GPU
            ds_cmpst_rtn_b32 v0, v0, v4, v3
            ^

In RDNA 3, 'ds_cmpst_[...]' has been replaced by 'ds_cmpstore_[...]', and the
notes for 'ds_cmpst_[...]' in pre-RDNA 3 ISA manuals:

    Caution, the order of src and cmp are the *opposite* of the BUFFER_ATOMIC_CMPSWAP opcode.

..., have been resolved for 'ds_cmpstore_[...]' in the RDNA 3 ISA manual:

    In this architecture the order of src and cmp agree with the BUFFER_ATOMIC_CMPSWAP opcode.

..., and therefore '%2', '%3' now swapped with regards to GCC operand order.
Most of the affected libgomp OpenACC test cases then PASS their execution test.

	gcc/
	* config/gcn/gcn.md (sync_compare_and_swap<mode>_lds_insn)
	[TARGET_RDNA3]: Adjust.