Add QNN EP HTP shared memory allocator (#23136)
Adds QNN EP HTP shared memory allocator.
The HTP shared memory allocator (`HtpSharedMemoryAllocator`) calls the
rpcmem shared library (libcdsprpc.so/dll) to allocate and free memory
that can be shared between HTP and CPU.
The allocator can be enabled by setting QNN EP option
`enable_htp_shared_memory_allocator` to `1`.
`QNNExecutionProvider::CreatePreferredAllocators()` will then return an
instance of `HtpSharedMemoryAllocator`.
For each QNN context, we also need to register and unregister memory
handles in order to use the HTP shared memory. This memory handle
management is added to `QnnBackendManager`, which also manages the QNN
context handles.
For more information about using HTP shared memory with QNN, see:
https://docs.qualcomm.com/bundle/publicresource/topics/80-63442-50/htp_shared_buffer_tutorial.html#shared-buffer-tutorial
Limitations:
- HTP shared memory usage is only supported for graph inputs and
outputs. Intermediate values are not supported.
- An allocation is assigned to a single shared memory buffer. The
allocator is not smart enough to have multiple allocations share a
single shared memory buffer.
Co-authored-by: Baiju Meswani <bmeswani@microsoft.com>
