Fix: GPU Incorrect Padding For Globals

A float array use different alignment and reservation rules on
GPU versus CPU. Before this change the _pad1 was aligned to 16 bytes as
it was defined as an array, but on CPU this alignment doesn't
happen.

This is fixed by using 3 floats in stead of a float array for padding.

Pull Request: https://projects.blender.org/blender/blender/pulls/112565

source/blender/draw/intern/draw_common_shader_shared.h

@@ -135,7 +135,7 @@ struct GlobalsUboStorage {
   float size_checker;
   float size_vertex_gpencil;
   float fresnel_mix_edit;
-  float _pad[3];
+  float _pad1, _pad2, _pad3;
 };
 BLI_STATIC_ASSERT_ALIGN(GlobalsUboStorage, 16)