PC::make_alike<Allocator>

Change the template default of `make_alike<>()` to use the
same allocator as the creating allocator. This is a breaking
change.

In practice, this was so far used to create a pinned allocator,
e.g., for I/O operations. It is more sensible to create the
same allocator if unspecified as the creating PC and it
also makes "modern"/future AMReX, which uses PCs with
`PolymorphicArena` allocators, shorter/cleaner in user
code.

Author: ax3l

Src/Particle/AMReX_ParticleContainer.H

@@ -1370,14 +1370,14 @@ public:
     /** Create an empty particle container
      *
      * This creates a new AMReX particle container type with same compile-time
-     * and run-time attributes. But, it can change its allocator. This is
-     * helpful when creating temporary particle buffers for filter operations
+     * and run-time attributes. But, it can change its allocator (default: same allocator).
+     * This is helpful when creating temporary particle buffers for filter operations
      * and device-to-host copies.
      *
-     * @tparam Allocator AMReX allocator, e.g., amrex::PinnedArenaAllocator
+     * @tparam Allocator AMReX allocator, e.g., amrex::PinnedArenaAllocator, default: same allocator as the creating PC
      * @return an empty particle container
      * */
-    template <template<class> class NewAllocator=amrex::DefaultAllocator>
+    template <template<class> class NewAllocator=Allocator>
     ContainerLike<NewAllocator>
     make_alike () const
     {