v0.12.21

Enzyme v0.12.21

Diff since v0.12.20

Merged pull requests:

• Fix LLVM feature check (#1581) (@wsmoses)
• Add hvp helpers (#1583) (@wsmoses)
• Fixup batched calling conv (#1586) (@wsmoses)

Closed issues:

• Simpler example of a hard crash during Forward-over-Reverse (#1385)
• Enzyme support for TimerOutputs.jl (#1480)
• Enzyme doesn't work for AdvancedVI Part III: logpdf(MvNormal) + Base.Fix1 + mean(f, x) = error ??? (#1560)
• Enzyme API has some wrong argument types. (#1578)
• Enzyme produces inconsistent results with macros from UnPack.jl (#1579)
• LLVM version issue with latest release? (#1580)
• Inconsistent empty return type (#1584)