[ELF] -z separate-*: Use max-page-size instead of common-page-size for...

[ELF] -z separate-*: Use max-page-size instead of common-page-size for text/non-SHF_ALLOC transition and writeTrapInstr

For -z separate-code and -z separate-loadable-segments:

When RW is present, the RX to RW transition is aligned with max-page-size.
When RW is absent, the RX to non-SHF_ALLOC transition should use max-page-size as well.