tcg: Add temp allocation for TCGv_i128

This enables allocation of i128.  The type is not yet
usable, as we have not yet added data movement ops.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2 files changed