Install c10d headers with absolute path (pytorch#86257)

pytorch#85780 updated all c10d headers in pytorch to use absolute path following the other distributed components. However, the headers were still copied to `${TORCH_INSTALL_INCLUDE_DIR}/torch`, thus external extentions still have to reference the c10d headers as `<c10d/*.h>`, making the usage inconsistent (the only exception was c10d/exception.h, which was copied to `${TORCH_INSTALL_INCLUDE_DIR}/torch/csrc/distributed/c10d`).

This patch fixes the installation step to copy all c10d headers to `${TORCH_INSTALL_INCLUDE_DIR}/torch/csrc/distributed/c10d`, thus external extensions can consistently reference c10d headers with the absolute path.

Pull Request resolved: pytorch#86257
Approved by: https://github.com/kumpera

caffe2/CMakeLists.txt

@@ -1147,9 +1147,6 @@ endif()
 install(DIRECTORY "${TORCH_SRC_DIR}/csrc"
   DESTINATION ${TORCH_INSTALL_INCLUDE_DIR}/torch
   FILES_MATCHING PATTERN "*.h" PATTERN "*.hpp")
-install(DIRECTORY "${TORCH_SRC_DIR}/csrc/distributed/c10d"
-  DESTINATION ${TORCH_INSTALL_INCLUDE_DIR}
-  FILES_MATCHING PATTERN "*.h" PATTERN "*.hpp")
 install(FILES
   "${TORCH_SRC_DIR}/script.h"
   "${TORCH_SRC_DIR}/extension.h"

setup.py

@@ -1062,8 +1062,6 @@ def main():
         'include/c10/cuda/impl/*.h',
         'include/c10/hip/*.h',
         'include/c10/hip/impl/*.h',
-        'include/c10d/*.h',
-        'include/c10d/*.hpp',
         'include/caffe2/**/*.h',
         'include/torch/*.h',
         'include/torch/csrc/*.h',
@@ -1094,7 +1092,8 @@ def main():
         'include/torch/csrc/deploy/*.h',
         'include/torch/csrc/deploy/interpreter/*.h',
         'include/torch/csrc/deploy/interpreter/*.hpp',
-        'include/torch/csrc/distributed/c10d/exception.h',
+        'include/torch/csrc/distributed/c10d/*.h',
+        'include/torch/csrc/distributed/c10d/*.hpp',
         'include/torch/csrc/distributed/rpc/*.h',
         'include/torch/csrc/jit/*.h',
         'include/torch/csrc/jit/backends/*.h',