[SYCL][Bindless][3/4] Add experimental implementation of SYCL bindless images extension

This commit stands as the third commit of four to make code review easier,
mostly covering the changes made to the user-facing SYCL API for the
bindless images extension.

The bindless images extension provides a new interface for allocating,
creating, and accessing images in SYCL. Image memory allocation is
seperated from image handle creation, and image handles can be passed
to kernels without requesting access through accessors. This approach
provides much more flexibility to the user, as well as enabling programs
to implement features that were impossible to implement using standard
SYCL images, such as a texture atlas. In addition to providing a new
interface for images, this extension also provides initial experimental
support for importing external memory into SYCL.

Co-authored-by: Isaac Ault <isaac.ault@codeplay.com>
Co-authored-by: Hugh Bird <hugh.bird@codeplay.com>
Co-authored-by: Duncan Brawley <duncan.brawley@codeplay.com>
Co-authored-by: Przemek Malon <przemek.malon@codeplay.com>
Co-authored-by: Chedy Najjar <chedy.najjar@codeplay.com>
Co-authored-by: Sean Stirling <sean.stirling@codeplay.com>
Co-authored-by: Peter Zuzek <peter@codeplay.com>

Implement revision 4 of the bindless images extension proposal: intel#9842

Author: SYCL Unbound Team

sycl/include/sycl/detail/cg.hpp

@@ -73,6 +73,9 @@ class CG {
     CopyFromDeviceGlobal = 20,
     ReadWriteHostPipe = 21,
     ExecCommandBuffer = 22,
+    CopyImage = 23,
+    SemaphoreWait = 24,
+    SemaphoreSignal = 25,
   };
 
   struct StorageInitHelper {
@@ -496,6 +499,77 @@ class CGCopyFromDeviceGlobal : public CG {
   size_t getNumBytes() { return MNumBytes; }
   size_t getOffset() { return MOffset; }
 };
+/// "Copy Image" command group class.
+class CGCopyImage : public CG {
+  void *MSrc;
+  void *MDst;
+  sycl::detail::pi::PiMemImageDesc MImageDesc;
+  sycl::detail::pi::PiMemImageFormat MImageFormat;
+  sycl::detail::pi::PiImageCopyFlags MImageCopyFlags;
+  sycl::detail::pi::PiImageOffset MSrcOffset;
+  sycl::detail::pi::PiImageOffset MDstOffset;
+  sycl::detail::pi::PiImageRegion MHostExtent;
+  sycl::detail::pi::PiImageRegion MCopyExtent;
+
+public:
+  CGCopyImage(void *Src, void *Dst, sycl::detail::pi::PiMemImageDesc ImageDesc,
+              sycl::detail::pi::PiMemImageFormat ImageFormat,
+              sycl::detail::pi::PiImageCopyFlags ImageCopyFlags,
+              sycl::detail::pi::PiImageOffset SrcOffset,
+              sycl::detail::pi::PiImageOffset DstOffset,
+              sycl::detail::pi::PiImageRegion HostExtent,
+              sycl::detail::pi::PiImageRegion CopyExtent,
+              CG::StorageInitHelper CGData, detail::code_location loc = {})
+      : CG(CopyImage, std::move(CGData), std::move(loc)), MSrc(Src), MDst(Dst),
+        MImageDesc(ImageDesc), MImageFormat(ImageFormat),
+        MImageCopyFlags(ImageCopyFlags), MSrcOffset(SrcOffset),
+        MDstOffset(DstOffset), MHostExtent(HostExtent),
+        MCopyExtent(CopyExtent) {}
+
+  void *getSrc() const { return MSrc; }
+  void *getDst() const { return MDst; }
+  sycl::detail::pi::PiMemImageDesc getDesc() const { return MImageDesc; }
+  sycl::detail::pi::PiMemImageFormat getFormat() const { return MImageFormat; }
+  sycl::detail::pi::PiImageCopyFlags getCopyFlags() const {
+    return MImageCopyFlags;
+  }
+  sycl::detail::pi::PiImageOffset getSrcOffset() const { return MSrcOffset; }
+  sycl::detail::pi::PiImageOffset getDstOffset() const { return MDstOffset; }
+  sycl::detail::pi::PiImageRegion getHostExtent() const { return MHostExtent; }
+  sycl::detail::pi::PiImageRegion getCopyExtent() const { return MCopyExtent; }
+};
+
+/// "Semaphore Wait" command group class.
+class CGSemaphoreWait : public CG {
+  sycl::detail::pi::PiInteropSemaphoreHandle MInteropSemaphoreHandle;
+
+public:
+  CGSemaphoreWait(
+      sycl::detail::pi::PiInteropSemaphoreHandle InteropSemaphoreHandle,
+      CG::StorageInitHelper CGData, detail::code_location loc = {})
+      : CG(SemaphoreWait, std::move(CGData), std::move(loc)),
+        MInteropSemaphoreHandle(InteropSemaphoreHandle) {}
+
+  sycl::detail::pi::PiInteropSemaphoreHandle getInteropSemaphoreHandle() const {
+    return MInteropSemaphoreHandle;
+  }
+};
+
+/// "Semaphore Signal" command group class.
+class CGSemaphoreSignal : public CG {
+  sycl::detail::pi::PiInteropSemaphoreHandle MInteropSemaphoreHandle;
+
+public:
+  CGSemaphoreSignal(
+      sycl::detail::pi::PiInteropSemaphoreHandle InteropSemaphoreHandle,
+      CG::StorageInitHelper CGData, detail::code_location loc = {})
+      : CG(SemaphoreSignal, std::move(CGData), std::move(loc)),
+        MInteropSemaphoreHandle(InteropSemaphoreHandle) {}
+
+  sycl::detail::pi::PiInteropSemaphoreHandle getInteropSemaphoreHandle() const {
+    return MInteropSemaphoreHandle;
+  }
+};
 
 /// "Execute command-buffer" command group class.
 class CGExecCommandBuffer : public CG {