[llvm-branch-commits] [llvm] [llvm][cmake] Turn runtime in PROJECTS warnings into FATAL_ERROR (PR #152302)

[David Spickett via llvm-branch-commits]

DavidSpickett wrote:

The alternative is to bump 21 to 22 in the messages on the 21.x branch, and turn them into errors on main instead.

https://github.com/llvm/llvm-project/pull/152302