Add support for UNWIND_X86_64_MODE_STACK_IND entries.
Correct the function offset computations in UNWIND_SECOND_LEVEL_REGULAR
tables.  A few other small fixes.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@222910 91177308-0d34-0410-b5e6-96231b3b80d8