There is no point in encoding load/store within a bit of
the memory trace info operand. Represent atomic operations
as a single read-modify-write tracepoint. Use MemOpIdx
instead of inventing a form specifically for traces.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>