Integrate libTorch CMake recipe into GROMACS main

gromacs/gromacs-mdmodules/gmxManageColvars.cmake.diff

@@ -1,15 +1,24 @@
-diff --git a/gromacs/gromacs-mdmodules/cmake/gmxManageColvars.cmake b/gromacs/gromacs-mdmodules/cmake/gmxManageColvars.cmake
-index 90778221..645b23b5 100644
+diff --git a/cmake/gmxManageColvars.cmake b/cmake/gmxManageColvars.cmake
+index 9077822166..9a6ed2564d 100644
 --- a/cmake/gmxManageColvars.cmake
 +++ b/cmake/gmxManageColvars.cmake
-@@ -54,6 +54,11 @@ function(gmx_manage_colvars)
+@@ -54,6 +54,20 @@ function(gmx_manage_colvars)
          target_sources(colvars INTERFACE $<TARGET_OBJECTS:colvars_objlib>)
          target_include_directories(colvars SYSTEM INTERFACE $<BUILD_INTERFACE:${COLVARS_DIR}>)
- 
+
 +        if(GMX_OPENMP)
 +            target_compile_options(colvars_objlib PRIVATE ${OpenMP_CXX_FLAGS})
 +            target_link_libraries(colvars_objlib PRIVATE OpenMP::OpenMP_CXX)
 +        endif()
++
++        find_package(Torch)
++        if (Torch_FOUND)
++          set_property(TARGET colvars PROPERTY CXX_STANDARD 17)
++          target_compile_definitions(colvars PRIVATE -DTORCH)
++          target_compile_options(colvars PRIVATE ${CMAKE_CXX_FLAGS} ${TORCH_CXX_FLAGS})
++          target_include_directories(colvars PRIVATE ${TORCH_INCLUDE_DIRS})
++          target_link_libraries(libgromacs PRIVATE "${TORCH_LIBRARIES}")
++        endif()
 +
      else()
          # Create a dummy link target so the calling code doesn't need to know