[clang] [C++20] [Modules] Fix thread_local variable handling in modules (PR #189796)

[Hans Wennborg via cfe-commits]

zmodem wrote:

> Maybe the test should specify an explicit triple?

Let's say that with a patch instead :) https://github.com/llvm/llvm-project/pull/189937

https://github.com/llvm/llvm-project/pull/189796