AssemblyScript's latest compiler 0.18 exports __new__/__pin__/unpin APIs to allocate/retain/free memory instead of __new/__retain/__release APIs in older version, we lookup functions of both version to make it compatible for both version.
Modify the macro control sentences as darwin platform doesn't support mmap with MAP_32BIT flag to put the mapping address into 0-2G range.
Co-authored-by: Wenyong Huang <wenyong.huang@intel.com>
