[clang] [clang][win] Define vector deleting dtor body for declared-only dtor if needed (PR #185653)

[Hans Wennborg via cfe-commits]

zmodem wrote:

The linked bug does say "reverting it locally fixed the testing failures" which is a pretty strong indication.

I'm afraid we don't have a small reproducer yet, but https://crbug.com/493894786#comment4 and forward has a call stack and disassembly.

It looks like we're failing a control-flow guard check when calling a virtual destructor. I'm guessing that relates to the newly emitted vector deleting dtor.

We'll keep digging :-)

https://github.com/llvm/llvm-project/pull/185653