Check that sections are appropriately separated in virtual memory,
based on their (expected) permissions. This checks for missing
-Wl,-z,separate-code and potentially other problems.
Co-authored-by: fanquake <fanquake@gmail.com>
This is a partial backport of core#19525 and core#20346
https://github.com/bitcoin/bitcoin/pull/19525/commits/65d0f1a53354fb25c8152ee5b430cf57e6508594
Depends on D13575