Disable MCJIT on non-Darwin platforms
Disable MCJIT on non-Darwin platforms

Currently the runtime dynamic linker lacks object file support for anything
other than Mach-O.

git-svn-id: b33bab8abb5b18c12ee100cd7761ab452d00b2b0@132583 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb