[clang] [llvm] [clang][Modules][serialization] Deduplicate source location entries across loaded modules (PR #209795)

[Jonas Hahnfeld via llvm-commits]

hahnjo wrote:

I believe a comment by @ayokunle321, edited into a reply by @ChuanqiXu9

> Hi @ChuanqiXu9 I was able to fix this issue. Please see the reply I gave to @hahnjo. I also added your reproducer as a regression test. Please could you test it out on your end again. Thanks!

(I will restore the original comment because I was confused only reading the email notification)

https://github.com/llvm/llvm-project/pull/209795