target/s390x: fake instruction loading when handling 'ex'

target/s390x: fake instruction loading when handling 'ex'

The s390x EXecute instruction is a bit weird as we synthesis the
executed instruction from what we have stored in memory. This missed
the plugin instrumentation.

Work around this with a special helper to inform the rest of the
translator about the instruction so things stay consistent.

Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221027183637.2772968-26-alex.bennee@linaro.org>