tcg/sparc64: Use standard slow path for softmmu

tcg/sparc64: Use standard slow path for softmmu

Drop the target-specific trampolines for the standard slow path.
This lets us use tcg_out_helper_{ld,st}_args, and handles the new
atomicity bits within MemOp.

At the same time, use the full load/store helpers for user-only mode.
Drop inline unaligned access support for user-only mode, as it does
not handle atomicity.

Use TCG_REG_T[1-3] in the tlb lookup, instead of TCG_REG_O[0-2].
This allows the constraints to be simplified.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>