The header docs in SBDebugger.i suggest:
target = debugger.CreateTargetWithFileAndArch (exe, lldb.LLDB_ARCH_DEFAULT)
but that call doesn't actually produce a valid target. The equivalent API - FindTargetWithFileAndArch does work, because it uses the current platform to translate LLDB_ARCH_DEFAULT. This patch just adds that same step to CreateTargetWithFileAndArch, and adds a test.
This API was untested so I also added a test for this one and the similar CreateTargetWithFileAndTargetTriple.
I don't see anywhere where we say what the difference between an "Arch" and a "TargetTriple" is. If anybody has some good verbiage for that, I'll add it to the docs for the API.