Add the rest of the error checking for Mach-O dyld compact bind entry errors

and test cases for each of the error checks.

To do this more plumbing was needed so that the segment indexes and
segment offsets can be checked.  Basically what was done was the SegInfo
from llvm-objdump’s MachODump.cpp was moved into libObject for Mach-O
objects as BindRebaseSegInfo and it is only created when an iterator for
bind or rebase entries are created.

This commit really only adds the error checking and test cases for the
bind table entires and the checking for the lazy bind and weak bind entries
are still to be fully done as well as the rebase entires.  Though some of
the plumbing for those are added with this commit.  Those other error
checks and test cases will be added in follow on commits.

Note, the two llvm_unreachable() calls should now actually be unreachable
with the error checks in place and would take a logic bug in the error
checking code to be reached if the segment indexes and segment
offsets are used from a checked bind entry.  Comments have been added
to the methods that require the arguments to have been checked
prior to calling.

llvm-svn: 298292