Hexagon (target/hexagon) Move new_value to DisasContext

Hexagon (target/hexagon) Move new_value to DisasContext

The new_value array in the CPUHexagonState is only used for bookkeeping
within the translation of a packet.  With recent changes that eliminate
the need to free TCGv variables, these make more sense to be transient
and kept in DisasContext.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230427230012.3800327-18-tsimpson@quicinc.com>