This removes another way to obtain objects larger than PTRDIFF_MAX. The
only known remaining hole is now jemalloc's merging of virtual memory
spans.
Technically this could be wrapped in an __LP64__ ifndef since it can't
occur on 64-bit due to the 1:1 split. It doesn't really matter either
way.
Change-Id: Iab2af242b775bc98a59421994d87aca0433215bd
The mremap definition was incorrect (unsigned long instead of int) and
it was missing the optional new_address parameter.
Change-Id: Ib9d0675aaa098c21617cedc9b2b8cf267be3aec4