fix: defer rocshmem env var reading and align RDMA buffer size

- Update rocshmem submodule to commit with lazy env var reading,
  so ROCSHMEM_HEAP_SIZE set via os.environ can take effect before
  C++ library initialization
- Align num_rdma_bytes to 2GB boundary using bit shifts instead of
  magic numbers
- Update build.sh to checkout the new rocshmem commit
Signed-off-by: lijian <34831075+lijian0711@users.noreply.github.com>

build.sh

@@ -144,7 +144,7 @@ build_rocshmem()
     cd third-party/rocshmem/
     git config --global --add safe.directory .
     if [ "$BUILD_SHCA" == "ON" ]; then
-        git checkout 0a05c14ebd47034ed049afb7b896536fcd91a9a7
+        git checkout b118f9ea536d873fef9d411180e44c71900a0a32
     fi
     if [ ! -d "build" ]; then
         mkdir -p build

deep_ep/buffer.py

@@ -122,9 +122,8 @@ class Buffer:
 
             self.gda_num_qps_per_pe = max(int(os.environ.get('ROCSHMEM_GDA_NUM_QPS_PER_PE_DEFAULT_CTX', str(num_qps_per_rank))), num_qps_per_rank * self.group_size)
             os.environ["ROCSHMEM_GDA_NUM_QPS_DEFAULT_CTX"] = str(self.gda_num_qps_per_pe)
-            if self.num_rdma_bytes > 1073741824:
-                multiple = 2147483648
-                rocshmem_num_rdma_bytes = ((self.num_rdma_bytes + multiple - 1) // multiple) * multiple
+            if self.num_rdma_bytes > (1 << 30):
+                rocshmem_num_rdma_bytes = ((self.num_rdma_bytes + (1 << 31) - 1) // (1 << 31)) * (1 << 31)
                 os.environ["ROCSHMEM_HEAP_SIZE"] = str(rocshmem_num_rdma_bytes)
             if self.group_size <= 8:
                 os.environ["ROCSHMEM_BACKEND"] = "ipc"

rocshmem @ da2fa573

-Subproject commit bea1a2e7dc6abaa40d4def4800bb1eef52735e2b
+Subproject commit da2fa573cca9c363e5ff7e399a5030d1608657a6