Re-apply "[ORC] Add N_SO and N_OSO stabs entries to MachO debug..." with fixes.

This re-applies db51e572893, which was reverted in 05b1a2cb3e6 due to bot
failures. The DebuggerSupportPlugin now depends on DWARF, so it has been moved
to the new OrcDebugging library (as has the enableDebuggerSupport API).

GitOrigin-RevId: b2518971d82331b09d7630ac1aecbb49e876a496
9 files changed