Fix some sources of invalidations

- Base already defines a IndexStyle(::AbstractArray) method for object arguments
  that uses the object type, so we can implement that directly and avoid the
  invalidations from implement Base.IndexStyle(::PyObjectArray).
- The Dates stdlib already defines a method that does the same thing for any
  `Period`.

Author: JamesWrigley

src/JlWrap/objectarray.jl

@@ -10,7 +10,7 @@ PyObjectArray(x::AbstractArray{T,N}) where {T,N} = PyObjectArray{N}(x)
 
 pyobjectarray_finalizer(x::PyObjectArray) = GC.enqueue_all(x.ptrs)
 
-Base.IndexStyle(x::PyObjectArray) = Base.IndexStyle(x.ptrs)
+Base.IndexStyle(T::Type{<: PyObjectArray}) = Base.IndexStyle(fieldtype(T, :ptrs))
 
 Base.length(x::PyObjectArray) = length(x.ptrs)
 

src/NumpyDates/InlineTimeDelta64.jl

@@ -24,8 +24,6 @@ end
 
 # accessors
 
-Dates.value(d::InlineTimeDelta64) = d.value
-
 unitpair(::InlineTimeDelta64{U}) where {U} = unitpair(U)
 unitpair(::Type{InlineTimeDelta64{U}}) where {U} = unitpair(U)
 

src/NumpyDates/TimeDelta64.jl

@@ -23,8 +23,6 @@ end
 
 # accessors
 
-Dates.value(d::TimeDelta64) = d.value
-
 unitpair(d::TimeDelta64) = d.unit
 
 # constructors