Fix cmake not triggering rebuild on .glsl changes

At least on windows we do not re-run datatoc when the .glsl files change.

To test is simple, just change edit_mesh_overlay_common_lib.glsl
remove lines, write plain text, ..., now rebuild and go in edit mode
with the default cube.

I also had to remove the entry in gpu/CMakeLists.txt for
gpu_shader_material.glsl since this was being tracked directly, as well
as running data_to_c_simple (otherwise CMake raises an error for
duplicated entries).

We probably want to do the same for the other datatoc functions.

Reviewers: LazyDodo, brecht
Differential Revision: https://developer.blender.org/D3803

build_files/cmake/macros.cmake

@@ -1232,6 +1232,8 @@ function(data_to_c_simple
 	get_filename_component(_file_to   ${CMAKE_CURRENT_BINARY_DIR}/${file_from}.c REALPATH)
 
 	list(APPEND ${list_to_add} ${_file_to})
+	source_group(Generated FILES ${_file_to})
+	list(APPEND ${list_to_add} ${file_from})
 	set(${list_to_add} ${${list_to_add}} PARENT_SCOPE)
 
 	get_filename_component(_file_to_path ${_file_to} PATH)

source/blender/gpu/CMakeLists.txt

@@ -87,8 +87,6 @@ set(SRC
 	intern/gpu_vertex_format.c
 	intern/gpu_viewport.c
 
-	shaders/gpu_shader_material.glsl
-
 	GPU_attr_binding.h
 	GPU_batch.h
 	GPU_batch_presets.h