Revert "Merge pull request #22441 from JuliaLang/jq/array-union-bits"

This reverts commit d126c66, reversing
changes made to a945af3.

Author: andreasnoack

base/array.jl

@@ -109,36 +109,8 @@ size(a::Array{<:Any,N}) where {N} = (@_inline_meta; ntuple(M -> size(a, M), Val(
 
 asize_from(a::Array, n) = n > ndims(a) ? () : (arraysize(a,n), asize_from(a, n+1)...)
 
-"""
-    Base.isbitsunion(::Type{T})
-
-Return whether a type is an "is-bits" Union type, meaning each type included in a Union is `isbits`.
-"""
-function isbitsunion end
-
-function isbitsunion(U::Union)
-    for u in Base.uniontypes(U)
-        isbits(u) || return false
-    end
-    return true
-end
-isbitsunion(T) = false
-
-"""
-    Base.bitsunionsize(U::Union)
-
-For a Union of `isbits` types, return the size of the largest type.
-"""
-function bitsunionsize(U::Union)
-    sz = 0
-    for u in Base.uniontypes(U)
-        sz = max(sz, sizeof(u))
-    end
-    return sz
-end
-
 length(a::Array) = arraylen(a)
-elsize(a::Array{T}) where {T} = isbits(T) ? sizeof(T) : (isbitsunion(T) ? bitsunionsize(T) : sizeof(Ptr))
+elsize(a::Array{T}) where {T} = isbits(T) ? sizeof(T) : sizeof(Ptr)
 sizeof(a::Array) = Core.sizeof(a)
 
 function isassigned(a::Array, i::Int...)
@@ -215,7 +187,7 @@ original.
 copy(a::T) where {T<:Array} = ccall(:jl_array_copy, Ref{T}, (Any,), a)
 
 function reinterpret(::Type{T}, a::Array{S,1}) where T where S
-    nel = Int(div(length(a) * sizeof(S), sizeof(T)))
+    nel = Int(div(length(a)*sizeof(S),sizeof(T)))
     # TODO: maybe check that remainder is zero?
     return reinterpret(T, a, (nel,))
 end
@@ -234,7 +206,7 @@ function reinterpret(::Type{T}, a::Array{S}, dims::NTuple{N,Int}) where T where
     end
     isbits(T) || throwbits(S, T, T)
     isbits(S) || throwbits(S, T, S)
-    nel = div(length(a) * sizeof(S), sizeof(T))
+    nel = div(length(a)*sizeof(S),sizeof(T))
     if prod(dims) != nel
         _throw_dmrsa(dims, nel)
     end