target/arm: Move do_coproc_insn() syndrome calculation earlier

target/arm: Move do_coproc_insn() syndrome calculation earlier

Rearrange the code in do_coproc_insn() so that we calculate the
syndrome value for a potential trap early; we're about to add a
second check that wants this value earlier than where it is currently
determined.

(Specifically, a trap to EL2 because of HSTR_EL2 should take
priority over an UNDEF to EL1, even when the UNDEF is because
the register does not exist at all or because its ri->access
bits non-configurably fail the access. So the check we put in
for HSTR_EL2 trapping at EL1 (which needs the syndrome) is
going to have to be done before the check "is the ARMCPRegInfo
pointer NULL".)

This commit is just code motion; the change to HSTR_EL2
handling that will use the 'syndrome' variable is in a
subsequent commit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-5-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-5-peter.maydell@linaro.org