[clang] [C++][Modules] A module directive may only appear as the first preprocessing tokens in a file (PR #144233)

[via cfe-commits]

yronglin wrote:

> This causes a large compile-time regression: https://llvm-compile-time-tracker.com/compare.php?from=1b5d6ec6855369d109fcb740ecd3812231b7a279&to=ea321392ebc487c1000e43576f44af99edf28a5f&stat=instructions:u

Thanks report this issue! This my first time to use this website and I have a few questions, I was wondering if you can help me:
1. IIUC, `42935M | 43035M (+0.23%)`does this mean the compiler output binary size increased by 0.23%?
2. If I try to fix this in a new PR, is there a way for me to test the data with this site before merging the PR?

https://github.com/llvm/llvm-project/pull/144233