hugr-llvm: v0.15.0

Bug Fixes

• Rename widen insta tests (#1949)

New Features

• Emit widen ops from the int ops extension (#1946)
• [breaking] replace Lift with Barrier (#1952)
• (hugr-llvm) Emit narrow ops (#1955)
• Add float <--> int bytecasting ops to conversions extension (#1956)
• (hugr-llvm) Emit iu_to_s and is_to_u (#1978)

Refactor

• [breaking] remove unused dependencies (#1935)