[X86] AMD Zen 3: _REV variants of zero-cycles moves are also zero-cycles (PR50261)

[X86] AMD Zen 3: _REV variants of zero-cycles moves are also zero-cycles (PR50261)

Sometimes disassembler picks _REV variants of instructions
over the plain ones, which in this case exposed an issue
that the _REV variants aren't being modelled as optimizable moves.