Change the mechanism around SBValue::GetSP() so that it always requires the target API lock AND the
process StopLocker (if there is a process) before it will hand out SBValues.  We were doing this in
an ad hoc fashion previously, and then playing whack-a-mole whenever we found a place where we should
have been doing this but weren't.  Really, it doesn't make sense to be poking at SBValues when the target
is running, the dynamic and synthetic values can't really be computed, and the underlying memory may be
incoherent.

<rdar://problem/13819378> Sometimes when stepping fast, my inferior is killed by debugserver
ELFRelocationEntry::operator<(): Try to stabilize the order. r_offset was insufficient to sort Relocs.

It should fix llvm/test/CodeGen/ARM/ehabi-mc-compact-pr*.ll on some hosts.

  RELOCATION RECORDS FOR [.ARM.exidx]:
  0 R_ARM_PREL31 .text
  0 R_ARM_NONE __aeabi_unwind_cpp_pr0

FIXME: I am not sure of the directions of extra comparators, in Type and Index.
For now, they are different from the direction in r_offset.