[clang] [clang][bytecode] Check if block is initialized before invoking destructor (PR #174082)

[Aiden Grossman via cfe-commits]

boomanaiden154 wrote:

Reverted in 22390cd7410f093528b95141d1d4d93ccf3573d9 to get the buildbots unblocked. Sorry for the inconvenience. I know this fixes a regression, but figured the revert shouldn't be too big of a deal given the bytecode interpreter isn't on by default anywhere (as far as I'm aware). I included a msan track origins stack trace in the commit message which might be helpful.

It's a use after destroy. We call `GlobalBlock->invokeDtor();` to destroy the object, and then try to use it again. I played around with it for a while, but couldn't get a fix that didn't break other tests.

https://github.com/llvm/llvm-project/pull/174082