Multi-data-section page protection assumes 4K pages

DR sets up a number of different data sections with different frequencies of self-protection and uses page protection syscalls to mark them read-only at certain points. However, we noticed that the section alignment has a hardcoded assumption of 4K pages, which is likely to lead to problems:

```
define DECLARE_DATA_SECTION(name, wx) \
asm(".section " name ", \"a" wx "\""); \
asm(".align 12"); /* 2^12 */
```

The data protection is currently only enabled on Windows IIRC which is likely why we never hit an issue on say an AArch64 machine with 64K pages.