Revert "[ VM ] Removed Dart_Allocate, Dart_AllocateWithNativeFields, and Dart_InvokeConstructor from embedding API"

This reverts commit 3d1b8b26c2282b27559a42c564035f946492e7cd.

Reason for revert: Broke Flutter HHH. Dart_AllocateWithNativeFields is still used in Tonic.

Original change's description:
> [ VM ] Removed Dart_Allocate, Dart_AllocateWithNativeFields, and Dart_InvokeConstructor from embedding API
> 
> These methods are no longer necessary and all objects should be created
> using Dart_New instead.
> 
> Change-Id: If64d3e3579fc03dd1a2eb6bfec73c35e90c66d8f
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/135523
> Reviewed-by: Ryan Macnak <rmacnak@google.com>

TBR=bkonyi@google.com,rmacnak@google.com,asiva@google.com

Change-Id: I3dca62a1db60a90bbcc78c34ae150df628cd85c8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/135642
Reviewed-by: Clement Skau <cskau@google.com>
Commit-Queue: Clement Skau <cskau@google.com>