Add host API for *_on_stream operations (#340)

* Add functional test for barrier_all_on_stream

* Add rocshmem_barrier_all_on_stream support for GDA and RO backends

Implements rocshmem_barrier_all_on_stream operation for
GPU Direct Access and Reverse Offload backends.

Previously, rocshmem_barrier_all_on_stream was only supported for IPC backend.

* Add functional test for rocshmem_broadcastmem_on_stream

* Add host-side rocshmem_broadcastmem_on_stream API

Implement stream-based broadcast collective operation

- Add rocshmem_broadcastmem_on_stream host API and kernel implementation
- Add functional test TeamBroadcastmemOnStreamTester with multi-stream
  support and correctness verification
- Use per-workgroup contexts to avoid contention across parallel streams

API:
rocshmem_broadcastmem_on_stream(team, dest, source, nelems, pe_root, stream)

* Add functional test for rocshmem_getmem_on_stream

* Add host-side rocshmem_getmem_on_stream API

Implement stream-based point-to-point RMA get operation

- Add rocshmem_getmem_on_stream host API and kernel implementation
- Support for asynchronous getmem operations on HIP streams
- Add backend support for GDA, RO, and IPC contexts
- Use work-group collective getmem for efficient memory transfer

API:
rocshmem_getmem_on_stream(dest, source, nelems, pe, stream)

(AI Assist)

* Add host-side rocshmem_putmem_on_stream API

- Add rocshmem_putmem_on_stream for asynchronous remote writes
- Support for concurrent RMA operations on HIP streams
- Add backend support for GDA, RO, and IPC contexts
- Use work-group device collective operation

API:
rocshmem_putmem_on_stream(dest, source, bytes, pe, stream)

(AI Assist)

* Add functional test for rocshmem_putmem_on_stream

* Add host-side rocshmem_putmem_signal_on_stream API

Enables asynchronous putmem operations with signaling on HIP streams.

The implementation includes:
- Kernel wrapper rocshmem_putmem_signal_kernel
- Host interface putmem_signal_on_stream method
- Context layer support across all backends (IPC, GDA, RO)
- Public API

Function signature:
void rocshmem_putmem_signal_on_stream(void *dest, const void *source,
                                      size_t bytes, uint64_t *sig_addr,
                                      uint64_t signal, int sig_op,
                                      int pe, hipStream_t stream);

* Add functional test for rocshmem_putmem_signal_on_stream

* Add host-side rocshmem_signal_wait_until_on_stream API

Enables asynchronous signal wait operations on HIP streams.

The implementation includes:
- Kernel wrapper rocshmem_signal_wait_until_kernel
- Host interface signal_wait_until_on_stream method
- Context layer support across all backends (IPC, GDA, RO)
- Native uint64_t support in wait_until API (generated from P2P_SYNC.py)

Function signature:
void rocshmem_signal_wait_until_on_stream(uint64_t *sig_addr, int cmp,
                                          uint64_t cmp_value,
                                          hipStream_t stream);

(AI Assist)

* Add functional test for rocshmem_signal_wait_until_on_stream

* Add documentation for stream API functions

This commit adds API documentation for the following host-side
stream functions:

- rocshmem_barrier_all_on_stream (collective routines)
- rocshmem_broadcastmem_on_stream (collective routines)
- rocshmem_getmem_on_stream (RMA operations)
- rocshmem_putmem_on_stream (RMA operations)
- rocshmem_putmem_signal_on_stream (signaling operations)
- rocshmem_signal_wait_until_on_stream (point-to-point sync)

The documentation includes function signatures, parameter descriptions,
and detailed explanations of asynchronous behavior and stream handling.

(AI Assist)

* Rename "bytes" -> "nelems"

* Add "_TEST_" to the variables used in tests

* Remove incorrect hipStreamDefault usage

hipStreamDefault is not a default stream. This is a flag.

If stream == nullptr, then just pass it to kernel. It will launch the kernel on the default stream

docs/api/pt2pt_sync.rst

@@ -96,6 +96,25 @@ ROCSHMEM_TEST
 **Description:**
 This routine tests if the condition ``(*ivars cmp val)`` is true.
 
+ROCSHMEM_SIGNAL_WAIT_UNTIL_ON_STREAM
+-------------------------------------
+
+.. cpp:function:: __host__ void rocshmem_signal_wait_until_on_stream(uint64_t *sig_addr, int cmp, uint64_t cmp_value, hipStream_t stream)
+
+  :param sig_addr:   Address of the signal variable on the symmetric heap.
+  :param cmp:        Comparison operator (e.g., ROCSHMEM_CMP_EQ, ROCSHMEM_CMP_GE, etc.).
+  :param cmp_value:  Value to compare against.
+  :param stream:     HIP stream on which to enqueue the operation.
+  :returns:          None.
+
+**Description:**
+This routine enqueues a wait operation on a HIP stream. The function blocks the calling thread
+until the signal variable at ``sig_addr`` satisfies the comparison condition ``(*sig_addr cmp cmp_value)``.
+The wait operation is executed asynchronously on the specified stream. The caller must synchronize
+the stream (e.g., using ``hipStreamSynchronize``) to ensure the wait condition has been satisfied.
+
+Valid ``cmp`` values are listed in :ref:`CMP_VALUES`.
+
 .. _CMP_VALUES:
 
 Supported comparisons