[clan-reply] Backport PTU error recovery to 20.x
This cherry-picks 3b4c51bb3243a02526313c51207a674139b67a00 and
beffd1509af7b12eeab0d5ae85b2f8322e039287 to 20.x.
Which are:
[clang-repl] Fix error recovery while PTU cleanup (#127467)
[clang][Interpreter] Disable part of lambda test on Windows
The latter commit avoids a test failure seen in Windows builds.
On main, I turned off one of the RUN lines for Windows, but reviewers
on the cherry-pick preferred UNSUPPORTED to disable the whole test.
So I have used UNSUPPORTED in this version for 20.x.
