Support for Model API for Selective Build in OSS (#11601)

### Summary
Added support for parsing the selected operators and dtypes directly
from an exported model to a `selected_operators.yaml` file. Previously,
operators had to be specified in string list or in a schema yaml file
for the selective build process. Now, a model can be specified at build
time (e.g. `-DEXECUTORCH_SELECT_OPS_FROM_MODEL="./mv2.pte"`) to parse
and select operators.


### Test plan
Added a test for this in
`examples/selective_build/test_selective_build.sh`. When run with `bash
examples/selective_build/test_selective_build.sh cmake` a resultant
`selected_operators.yaml` file is created at
`cmake-out/examples/selective_build/select_build_lib/selected_operators.yaml`
that conatins the selected operators as well as their dtypes.

Author: BujSet

examples/selective_build/CMakeLists.txt

@@ -61,6 +61,10 @@ option(EXECUTORCH_SELECT_OPS_LIST "Register a list of ops, separated by comma"
 option(EXECUTORCH_SELECT_ALL_OPS
        "Whether to register all ops defined in portable kernel library." OFF
 )
+
+# Option to enable parsing ops and dtypes directly from model pte file
+option(EXECUTORCH_SELECT_OPS_FROM_MODEL "Enable op selection from pte during build." OFF
+)
 # ------------------------------- OPTIONS END --------------------------------
 
 #
@@ -108,6 +112,8 @@ gen_selected_ops(
   "${EXECUTORCH_SELECT_OPS_LIST}"
   INCLUDE_ALL_OPS
   "${EXECUTORCH_SELECT_ALL_OPS}"
+  OPS_FROM_MODEL
+  "${EXECUTORCH_SELECT_OPS_FROM_MODEL}"
 )
 
 generate_bindings_for_kernels(

examples/selective_build/test_selective_build.sh

@@ -161,6 +161,29 @@ test_cmake_select_ops_in_yaml() {
     rm "./custom_ops_1.pte"
 }
 
+test_cmake_select_ops_in_model() {
+    echo "Exporting MobilenetV2"
+    ${PYTHON_EXECUTABLE} -m examples.portable.scripts.export --model_name="mv2"
+    local example_dir=examples/selective_build
+    local build_dir=cmake-out/${example_dir}
+    rm -rf ${build_dir}
+    retry cmake -DCMAKE_BUILD_TYPE=Release \
+            -DEXECUTORCH_SELECT_OPS_FROM_MODEL="./mv2.pte" \
+            -DCMAKE_INSTALL_PREFIX=cmake-out \
+            -DPYTHON_EXECUTABLE="$PYTHON_EXECUTABLE" \
+            -B${build_dir} \
+            ${example_dir}
+
+    echo "Building ${example_dir}"
+    cmake --build ${build_dir} -j9 --config Release
+
+    echo 'Running selective build test'
+    ${build_dir}/selective_build_test --model_path="./mv2.pte"
+
+    echo "Removing mv2.pte"
+    rm "./mv2.pte"
+}
+
 if [[ -z $BUCK ]];
 then
   BUCK=buck2
@@ -177,6 +200,7 @@ then
     test_cmake_select_all_ops
     test_cmake_select_ops_in_list
     test_cmake_select_ops_in_yaml
+    test_cmake_select_ops_in_model
 elif [[ $1 == "buck2" ]];
 then
     test_buck2_select_all_ops

tools/cmake/Codegen.cmake

@@ -12,18 +12,20 @@
 include(${EXECUTORCH_ROOT}/tools/cmake/Utils.cmake)
 
 function(gen_selected_ops)
-  set(arg_names LIB_NAME OPS_SCHEMA_YAML ROOT_OPS INCLUDE_ALL_OPS)
+  set(arg_names LIB_NAME OPS_SCHEMA_YAML ROOT_OPS INCLUDE_ALL_OPS OPS_FROM_MODEL)
   cmake_parse_arguments(GEN "" "" "${arg_names}" ${ARGN})
 
   message(STATUS "Generating operator lib:")
   message(STATUS "  LIB_NAME: ${GEN_LIB_NAME}")
   message(STATUS "  OPS_SCHEMA_YAML: ${GEN_OPS_SCHEMA_YAML}")
   message(STATUS "  ROOT_OPS: ${GEN_ROOT_OPS}")
   message(STATUS "  INCLUDE_ALL_OPS: ${GEN_INCLUDE_ALL_OPS}")
+  message(STATUS "  OPS_FROM_MODEL: ${GEN_OPS_FROM_MODEL}")
 
   set(_oplist_yaml
       ${CMAKE_CURRENT_BINARY_DIR}/${GEN_LIB_NAME}/selected_operators.yaml
   )
+
   file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${GEN_LIB_NAME})
 
   file(GLOB_RECURSE _codegen_tools_srcs "${EXECUTORCH_ROOT}/codegen/tools/*.py")
@@ -43,6 +45,9 @@ function(gen_selected_ops)
   if(GEN_INCLUDE_ALL_OPS)
     list(APPEND _gen_oplist_command --include_all_operators)
   endif()
+  if(GEN_OPS_FROM_MODEL)
+    list(APPEND _gen_oplist_command --model_file_path="${GEN_OPS_FROM_MODEL}")
+  endif()
 
   message("Command - ${_gen_oplist_command}")
   add_custom_command(