[SYCL] Revert recent copy requirements temporarily (intel#9970)

This commit reverts the recently introduced requirements on
`is_device_copyable` in copy commands. This is a temporary revert until
`sycl::vec` is made trivially copyable, to appropriately satisfy
`is_device_copyable` implicitly.

---------

Signed-off-by: Larsen, Steffen <steffen.larsen@intel.com>

sycl/include/sycl/handler.hpp

@@ -2289,8 +2289,8 @@ class __SYCL_EXPORT handler {
  "Invalid accessor target for the copy method.");
  static_assert(isValidModeForDestinationAccessor(AccessMode),
  "Invalid accessor mode for the copy method.");
- static_assert(is_device_copyable<T_Src>::value,
-  "Pattern must be device copyable");
+ // TODO: Add static_assert with is_device_copyable when vec is
+ // device-copyable.
  // Make sure data shared_ptr points to is not released until we finish
  // work with it.
  CGData.MSharedPtrStorage.push_back(Src);
@@ -2360,8 +2360,8 @@ class __SYCL_EXPORT handler {
  "Invalid accessor target for the copy method.");
  static_assert(isValidModeForDestinationAccessor(AccessMode),
  "Invalid accessor mode for the copy method.");
- static_assert(is_device_copyable<T_Src>::value,
-  "Pattern must be device copyable");
+ // TODO: Add static_assert with is_device_copyable when vec is
+ // device-copyable.
 #ifndef __SYCL_DEVICE_ONLY__
  if (MIsHost) {
  // TODO: Temporary implementation for host. Should be handled by memory