Fixed a potential crash if layout for a structure went wrong and we tried to get layout information that wasn't there.
Fixed a potential crash if layout for a structure
went wrong and we tried to get layout information
that wasn't there.

<rdar://problem/13490170>


git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@177880 91177308-0d34-0410-b5e6-96231b3b80d8

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