Fix: GPU Compositor results are sometimes clipped

Compositor outputs are sometimes clipped. That's because consecutive
shader operations in the GPU compositor were assumed to have the same
domain. So make sure to reset the domain during compile unit resets.

source/blender/compositor/realtime_compositor/intern/compile_state.cc

@@ -75,6 +75,7 @@ ShaderCompileUnit &CompileState::get_shader_compile_unit()
 void CompileState::reset_shader_compile_unit()
 {
   shader_compile_unit_.clear();
+  shader_compile_unit_domain_ = Domain::Identity();
 }
 
 bool CompileState::should_compile_shader_compile_unit(DNode node)