Introduce a new `Array.empty () : array 'a` primitive, define Array.copy and Array.init
requested to merge 342-patch-introduce-a-new-array-empty-array-a-primitive-define-array-copy-and-array-init into master
This patch introduces a new primitive function to create 0-length array without requiring an initialization element. This primitve makes it possible to define Array.copy and Array.init, which could previously not be implemented in the zero-size case.
Closes #342 (closed)