Hexagon (target/hexagon) cleanup ternary operators in semantics

Hexagon (target/hexagon) cleanup ternary operators in semantics

Change  (cond ? (res = x) : (res = y)) to res = (cond ? x : y)

This makes the semnatics easier to for idef-parser to deal with

The following instructions are impacted
    C2_any8
    C2_all8
    C2_mux
    C2_muxii
    C2_muxir
    C2_muxri

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-14-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>