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

[uditagarwal97]

Problem:

Currently, the image id of an RTDeviceBinaryImage instance is simply the pointer value of the underlying pi_device_binary (in getImageID()). 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 (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.

[steffenlarsen]

LGTM! 🚀