Prevent infinite recursion by adding a method unit(::Type{Any}) (#807)

Author: SeSodesa

src/utils.jl

@@ -145,6 +145,11 @@ true
 @inline unit(x::Type{Missing}) = missing
 @inline unit(x::Missing) = missing
 
+# Prevent infinite recursion, in case unit(Any) is called.
+@inline unit(x::Type{Any}) = throw(ArgumentError(
+    "unit(Any) was called, which has no meaningful result. This may be due to calling unit(eltype(…)), since eltype has a generic fallback method that returns Any."
+))
+
 """
     absoluteunit(::Units)
     absoluteunit(::Quantity)