Support dynamic resources

[bogner]

Support resources accessed via ResourceDescriptorHeap and SamplerDescriptorHeap

• End to end tests for heap resources in OffloadTests
• Handle accesses via heap in the resource binding map
• ResourceDescriptorHeap and SamplerDescriptorHeap symbols in clang
• [DirectX] Introduce llvm.dx.handle.fromHeap intrinsic and lowering llvm-project#91406

[hekota]

Closing this as we won't be using umbrella tasks like this going forward.