[Offload] Implement the remaining initial Offload API (#122106)

Implement the complete initial version of the Offload API, to the extent
that is usable for simple offloading programs. Tested with a basic SYCL
program.

As far as possible, these are simple wrappers over existing
functionality in the plugins.

* Allocating and freeing memory (host, device, shared).
* Creating a program 
* Creating a queue (wrapper over asynchronous stream resource)
* Enqueuing memcpy operations
* Enqueuing kernel executions
* Waiting on (optional) output events from the enqueue operations
* Waiting on a queue to finish

Objects created with the API have reference counting semantics to handle
their lifetime. They are created with an initial reference count of 1,
which can be incremented and decremented with retain and release
functions. They are freed when their reference count reaches 0. Platform
and device objects are not reference counted, as they are expected to
persist as long as the library is in use, and it's not meaningful for
users to create or destroy them.

Tests have been added to `offload.unittests`, including device code for
testing program and kernel related functionality.

The API should still be considered unstable and it's very likely we will
need to change the existing entry points.

1 files changed, 24 insertions, 4 deletions

diff --git a/offload/liboffload/API/Common.td b/offload/liboffload/API/Common.td
index 5b19d1d47129..de7502b54061 100644
--- a/offload/liboffload/API/Common.td
+++ b/offload/liboffload/API/Common.td
@@ -62,6 +62,27 @@ def : Handle {
   let desc = "Handle of context object";
 }
 
+def : Handle {
+  let name = "ol_queue_handle_t";
+  let desc = "Handle of queue object";
+}
+
+def : Handle {
+  let name = "ol_event_handle_t";
+  let desc = "Handle of event object";
+}
+
+def : Handle {
+  let name = "ol_program_handle_t";
+  let desc = "Handle of program object";
+}
+
+def : Typedef {
+  let name = "ol_kernel_handle_t";
+  let desc = "Handle of kernel object";
+  let value = "void *";
+}
+
 def : Enum {
   let name = "ol_errc_t";
   let desc = "Defines Return/Error codes";
@@ -69,12 +90,11 @@ def : Enum {
     Etor<"SUCCESS", "Success">,
     Etor<"INVALID_VALUE", "Invalid Value">,
     Etor<"INVALID_PLATFORM", "Invalid platform">,
-    Etor<"DEVICE_NOT_FOUND", "Device not found">,
     Etor<"INVALID_DEVICE", "Invalid device">,
-    Etor<"DEVICE_LOST", "Device hung, reset, was removed, or driver update occurred">,
-    Etor<"UNINITIALIZED", "plugin is not initialized or specific entry-point is not implemented">,
+    Etor<"INVALID_QUEUE", "Invalid queue">,
+    Etor<"INVALID_EVENT", "Invalid event">,
+    Etor<"INVALID_KERNEL_NAME", "Named kernel not found in the program binary">,
     Etor<"OUT_OF_RESOURCES", "Out of resources">,
-    Etor<"UNSUPPORTED_VERSION", "generic error code for unsupported versions">,
     Etor<"UNSUPPORTED_FEATURE", "generic error code for unsupported features">,
     Etor<"INVALID_ARGUMENT", "generic error code for invalid arguments">,
     Etor<"INVALID_NULL_HANDLE", "handle argument is not valid">,