PSA: You can run unittests with ninja now

This is just a heads up. As of r232212, if you’re using a CMake build you can type “ninja check-lldb-unit” and it will run the gtest suite. This should work on any platform. “ninja check-lldb” behavior is unchanged, but there is a TODO item to get “ninja check-lldb” to run both unit tests and the python API tests. I didn’t want to do it yet though because that has the potential to break build bots, so i wanted to keep it separate.

There is another TODO item to get this working in the Xcode build. Hopefully that will happen today or early next week.

The Xcode workspace might generate an error if you’re synched up to r232212. This is because gtest.xcodeproj has been deleted, and lldb.xcworkspace still refers to it. Fixing this should be a simple matter of removing the reference from lldb.xcworkspace to gtest.xcodeproj which I will get to today if nobody beats me.

Should we add a "test lldb-unit" to the bots?

Definitely, but I want to get some feedback first. For starters, the unit tests have been kind of rotting for a while, so I’m not sure they work everywhere (I got 2 failures on Windows). Secondly, the bots may not be prepared to parse their output yet.

so the best path forward is to probably have everyone try it out on their own respective platforms, we fix the failures (there’s only about 10 tests as is, so this should be easy), and then once it looks good we can update the builders.