llvm

a5ca431e - LLVM 21: Update for Attribute::NoCapture removal.

LLVM 21: Update for Attribute::NoCapture removal. LLVM 21 removes the nocapture attribute in favor of captures(none). Make sure we handle that. In tests where nocapture was not relevant to what was being tested and where it can be removed, remove it. In other tests, change the CHECK lines to permit both nocapture and captures(none).