iOS simulator cleanup to make sure we use "*-apple-ios" for iOS simulator apps and binaries.

Changes include:
- ObjectFileMachO can now determine if a binary is "*-apple-ios" or "*-apple-macosx" by checking the min OS and SDK load commands
- ArchSpec now says "<arch>-apple-macosx" is equivalent to "<arch>-apple-ios" since the simulator mixes and matches binaries (some from the system and most from the iOS SDK).
- Getting process inforamtion on MacOSX now correctly classifies iOS simulator processes so they have "*-apple-ios" architectures in the ProcessInstanceInfo
- PlatformiOSSimulator can now list iOS simulator processes correctly instead of showing nothing by using:
    (lldb) platform select ios-simulator
    (lldb) platform process list
- debugserver can now properly return "*-apple-ios" for the triple in the process info packets for iOS simulator executables
- GDBRemoteCommunicationClient now correctly passes along the triples it gets for process info by setting the OS in the llvm::Triple correctly

<rdar://problem/17060217>

llvm-svn: 209852