to the __PAGEZERO segment on darwin. The dynamic loader now correctly doesn't
slide __PAGEZERO and it also registers it as an invalid region of memory. This
allows us to not make any memory requests from the local or remote debug session
for any addresses in this region. Stepping performance can improve when uninitialized
local variables that point to locations in __PAGEZERO are attempted to be read
from memory as we won't even make the memory read or write request.
llvm-svn: 151128
over when running JITed expressions. The allocated memory cache will cache
allocate memory a page at a time for each permission combination and divvy up
the memory and hand it out in 16 byte increments.
llvm-svn: 131453