[llvm] [Offload] Erase entries from JIT cache when program is destroyed (PR #148847)

[Ross Brunton via llvm-commits]

================
@@ -854,6 +854,9 @@ Error GenericDeviceTy::unloadBinary(DeviceImageTy *Image) {
       return Err;
   }
 
+  if (Image->getTgtImageBitcode())
----------------
RossBrunton wrote:

If we are compiling bitcode, then this will be set to a `__tgt_device_image *` for the original bitcode that `olCreateProgram` copied. It is `nullptr` if no compilation took place (and so we don't need to tell the JIT to remove anything.

https://github.com/llvm/llvm-project/pull/148847