Enable LLDB to load large dSYM files. (#164471)
llvm-dsymutil can produce mach-o files where some sections in __DWARF
exceed the 4GB barrier and subsequent sections in the dSYM will be
inaccessible because the mach-o section_64 structure only has a 32 bit
file offset. This patch enables LLDB to load a large dSYM file by
figuring out when this happens and properly adjusting the file offset of
the LLDB sections.
I was unable to add a test as obj2yaml and yaml2obj are broken for
mach-o files and they can't convert a yaml file back into a valid mach-o
object file. Any suggestions for adding a test would be appreciated.
