[nvptx] Use atom.and.b64 instead of atom.b64.and

[nvptx] Use atom.and.b64 instead of atom.b64.and

The ptx manual prescribes the instruction format atom{.space}.op.type but the
compiler currently emits:
...
  atom.b64.and %r31, [%r30], %r32;
...
which uses the instruction format atom{.space}.type.op.

Fix this by emitting instead:
...
  atom.and.b64  %r31, [%r30], %r32;
...

Tested on nvptx.

gcc/ChangeLog:

2022-03-07  Tom de Vries  <tdevries@suse.de>

	* config/nvptx/nvptx.md (define_insn "atomic_fetch_<logic><mode>"):
	Emit atom.and.b64 instead of atom.b64.and.

gcc/testsuite/ChangeLog:

2022-03-07  Tom de Vries  <tdevries@suse.de>

	* gcc.target/nvptx/atomic_fetch-1.c: Update.
	* gcc.target/nvptx/atomic_fetch-2.c: Update.