Fixed an issue where if you specify an architecture from the command line like: $ lldb --arch i386-unknown-unknown a.out
Fixed an issue where if you specify an architecture from the command line like:
$ lldb --arch i386-unknown-unknown a.out

It would then create a target with only the "i386" part due to 
SBDebugger::GetDefaultArchitecture(...) truncating the arch triple due to the
way things used to be.



git-svn-id: b33bab8abb5b18c12ee100cd7761ab452d00b2b0@129731 91177308-0d34-0410-b5e6-96231b3b80d8

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