Change the code I added to LocateDSYMInVincinityOfExecutable to use the FileSpec methods for adding/removing file path components instead of using std::strings; feedback from Sean on the change I added in r305441. <rdar://problem/31825940>
Change the code I added to LocateDSYMInVincinityOfExecutable to use
the FileSpec methods for adding/removing file path components instead
of using std::strings; feedback from Sean on the change I added in
r305441.
<rdar://problem/31825940>

git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@305547 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 4b8d7de76594bab50c81345f8a2e578bb237f266)

apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb