Revert "[ORC] Initial MachO debugging support (via GDB JIT debug..."

llvm/include/llvm/ExecutionEngine/JITLink/JITLink.h

.../include/llvm/ExecutionEngine/Orc/DebuggerSupportPlugin.h

llvm/lib/ExecutionEngine/JITLink/JITLinkMemoryManager.cpp

llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp

llvm/lib/ExecutionEngine/Orc/CMakeLists.txt

llvm/lib/ExecutionEngine/Orc/DebuggerSupportPlugin.cpp

llvm/lib/ExecutionEngine/Orc/TargetProcess/JITLoaderGDB.cpp

...tionEngine/JITLink/X86/MachO_gdb_jit_debuginfo_register.s

...t/ExecutionEngine/JITLink/X86/MachO_skip_debug_sections.s

llvm/tools/llvm-jitlink/llvm-jitlink.cpp