tcg-i386: Fix win64 qemu store

The first non-register argument isn't placed at offset 0.

Cc: qemu-stable@nongnu.org
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
tci: Convert to new ldst opcodes

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg: Remove TCG_TARGET_HAS_new_ldst

Since all backends have been converted, remove the compatibility code.

Signed-off-by: Richard Henderson <rth@twiddle.net>