[clang] [Coverage] Handle array decomposition correctly (PR #88881)

[Eli Friedman via cfe-commits]

https://github.com/efriedma-quic approved this pull request.

LGTM.

I'm not completely convinced by your argument here... but let's try to move forward and land this and #88898 so we can do the refactor to use isUnique().  Then we can revisit later if necessary.

https://github.com/llvm/llvm-project/pull/88881