llvm-project

e3f87e15 - [C] Fix a false-positive with tentative defn compat (#139738)

[C] Fix a false-positive with tentative defn compat (#139738) C++ has a carve-out that makes a declaration with 'extern' explicitly specified and no initializer be a declaration rather than a definition. We now account for that to silence a diagnostic with: ``` extern const int i; const int i = 12; ``` which is valid C++. Addresses an issue that was brought up via post-commit review.