Skip building example executable when asked

examples/cpp-interface/CMakeLists.txt

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-add_executable(spirv-tools-cpp-example main.cpp)
-spvtools_default_compile_options(spirv-tools-cpp-example)
-target_link_libraries(spirv-tools-cpp-example PRIVATE SPIRV-Tools-opt)
+if (NOT ${SPIRV_SKIP_EXECUTABLES})
+  add_executable(spirv-tools-cpp-example main.cpp)
+  spvtools_default_compile_options(spirv-tools-cpp-example)
+  target_link_libraries(spirv-tools-cpp-example PRIVATE SPIRV-Tools-opt)
+endif()