Created by: egrimley
The stack pointer is passed as a third argument to relocate_dynamorio and on Linux this is used to search the auxiliary vector for AT_PAGESZ. Similarly, there are calls to os_page_size_init in dynamorio_app_init and standalone_init to do the same thing. On MacOS, and on Linux if for some reason os_page_size is called before these initialisations, the page size is discovered using the system calls mmap and munmap, which should work on any POSIX system.
A later commit should get Mac OSX to use sysctl_query on hw.pagesize.
Review-URL: https://codereview.appspot.com/313800043