[ORC][ORC-RT][MachO] Reset __data and __common sections on library close.

If we want to be able to close and then re-open a library then we need to reset
the data section states when the library is closed. This commit updates
MachOPlatform and the ORC runtime to track __data and __common sections, and
reset the state in MachOPlatformRuntimeState::dlcloseDeinitialize.

This is only a first step to full support -- there are other data sections that
we're not capturing, and we'll probably want a more efficient representation
for the sections (rather than passing their string name over IPC), but this is
a reasonable first step.

This commit also contains a fix to MapperJITLinkMemoryManager that prevents it
from calling OnDeallocated twice in the case of an error.