Add 60fps cutscene clamp for in-engine cinematics

Suspend the FPS unlock while a demo-manager Exec (DD sub_82184460 / EM sub_821856F8) ticks, so the frame-locked IngameCinematics Sequencer plays at native ~30fps instead of double speed. Adds ac6_cutscene_clamp CVar (default on).

thirdparty/rexglue-sdk/src/graphics/flags.cpp

@@ -31,6 +31,8 @@ REXCVAR_DEFINE_BOOL(use_fuzzy_alpha_epsilon, true, "GPU",
 REXCVAR_DEFINE_BOOL(vfetch_index_rounding_bias, false, "GPU/Shader",
                     "Apply small epsilon bias to vertex fetch indices before "
                     "flooring to fix black triangles caused by RCP precision");
+REXCVAR_DEFINE_BOOL(draw_resolution_scaled_texture_offsets, true, "GPU/Shader",
+                    "Scale texture offsets with draw resolution");
 REXCVAR_DEFINE_BOOL(gpu_debug_markers, false, "GPU",
                     "Insert debug markers into GPU command streams for tools "
                     "like PIX and RenderDoc. Automatically enabled when "