[SYCL] Ensure that RTDeviceBinaryImage instances have a unique image …

…ID (#12526)

**Problem:**

Currently, the image id of an RTDeviceBinaryImage instance is simply the
pointer value of the underlying pi_device_binary (in
[getImageID(](https://github.com/intel/llvm/blob/sycl/sycl/source/detail/device_binary_image.hpp#L221))).
However, consider the following scenario:
1) We create a device image
2) Put into cache
3) Destroy the image (when it goes out of scope)
4) Create another image that _happens to be created at the same memory
address_ (thus having same image ID)

This causes two instances of RTDeviceBinaryImage to share the same image
id, which ends up causing a collision in the KernelProgramCache.

**Solution (Proposed in this PR)**

Have a counter in RTDeviceBinaryImage that increments upon instantiation
of this class. The counter value is added to the image id to ensure that
no two instances have the same ID.

**Alternative Solutions**

1. Remove the entry from the KernelProgramCache when the image is
destroyed. This solution would require more work as the
KernelProgramCache, currently, [does not support arbitrary element-wise
eviction](https://github.com/intel/llvm/blob/sycl/sycl/doc/design/KernelProgramCache.md#in-memory-cache-eviction)
(eviction follows a LRU strategy when cache size exceeds the threshold).
Moreover, I expect this to have additional performance overhead of
having to lock the cache and evicting. The proposed solution is much
more simpler.

sycl/source/detail/device_binary_image.cpp

@@ -176,8 +176,13 @@ void RTDeviceBinaryImage::init(pi_device_binary Bin) {
   DeviceGlobals.init(Bin, __SYCL_PI_PROPERTY_SET_SYCL_DEVICE_GLOBALS);
   DeviceRequirements.init(Bin, __SYCL_PI_PROPERTY_SET_SYCL_DEVICE_REQUIREMENTS);
   HostPipes.init(Bin, __SYCL_PI_PROPERTY_SET_SYCL_HOST_PIPES);
+
+  if (Bin)
+    ImageId = ImageCounter++;
 }
 
+std::atomic<uintptr_t> RTDeviceBinaryImage::ImageCounter = 1;
+
 DynRTDeviceBinaryImage::DynRTDeviceBinaryImage(
     std::unique_ptr<char[]> &&DataPtr, size_t DataSize)
     : RTDeviceBinaryImage() {

sycl/source/detail/device_binary_image.hpp

@@ -220,7 +220,7 @@ class RTDeviceBinaryImage {
 
   std::uintptr_t getImageID() const {
     assert(Bin && "Image ID is not available without a binary image.");
-    return reinterpret_cast<std::uintptr_t>(Bin);
+    return ImageId;
   }
 
 protected:
@@ -240,6 +240,10 @@ class RTDeviceBinaryImage {
   RTDeviceBinaryImage::PropertyRange DeviceGlobals;
   RTDeviceBinaryImage::PropertyRange DeviceRequirements;
   RTDeviceBinaryImage::PropertyRange HostPipes;
+
+private:
+  static std::atomic<uintptr_t> ImageCounter;
+  uintptr_t ImageId;
 };
 
 // Dynamically allocated device binary image, which de-allocates its binary