target/arm: Expand pstate to 64 bits

target/arm: Expand pstate to 64 bits

The ARM now defines 36 bits in SPSR_ELx in aarch64 mode, so
it's time to bite the bullet and extend PSTATE to match.

Most changes are straightforward, adjusting printf formats,
changing local variable types.  More complex is migration,
where to maintain backward compatibility a new pstate64
record is introduced, and only when one of the extensions
that sets bits 32-35 are active.

The fate of gdbstub is left undecided for the moment.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20251008215613.300150-37-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>