Build: Fix some excessive Visual Studio compile times

While investigating Blender compilation time for windows-arm64, we
identified two compilation units that were taking a long time to compile
(~1h each). This affects windows-x64 builds as well.

Pull Request: https://projects.blender.org/blender/blender/pulls/117534

intern/cycles/kernel/integrator/shade_surface.h

@@ -238,10 +238,17 @@ integrate_direct_light_shadow_init_common(KernelGlobals kg,
 /* Path tracing: sample point on light and evaluate light shader, then
  * queue shadow ray to be traced. */
 template<uint node_feature_mask>
-ccl_device_forceinline void integrate_surface_direct_light(KernelGlobals kg,
-                                                           IntegratorState state,
-                                                           ccl_private ShaderData *sd,
-                                                           ccl_private const RNGState *rng_state)
+#if defined(__KERNEL_GPU__)
+ccl_device_forceinline
+#else
+/* MSVC has very long compilation time (x20) if we force inline this function */
+ccl_device
+#endif
+    void
+    integrate_surface_direct_light(KernelGlobals kg,
+                                   IntegratorState state,
+                                   ccl_private ShaderData *sd,
+                                   ccl_private const RNGState *rng_state)
 {
   /* Test if there is a light or BSDF that needs direct light. */
   if (!(kernel_data.integrator.use_direct_light && (sd->flag & SD_BSDF_HAS_EVAL))) {

source/blender/gpu/intern/gpu_shader_create_info.cc

@@ -413,6 +413,15 @@ void ShaderCreateInfo::validate_vertex_attributes(const ShaderCreateInfo *other_
 
 using namespace blender::gpu::shader;
 
+#ifdef _MSC_VER
+/* Disable optimization for this function with MSVC. It does not like the fact
+ * shaders info are declared in the same function (same basic block or not does
+ * not change anything).
+ * Since it is just a function called to register shaders (once),
+ * the fact it's optimized or not does not matter, it's not on any hot
+ * code path. */
+#  pragma optimize("", off)
+#endif
 void gpu_shader_create_info_init()
 {
   g_create_infos = new CreateInfoDictionnary();
@@ -553,6 +562,9 @@ void gpu_shader_create_info_init()
   /* TEST */
   // gpu_shader_create_info_compile(nullptr);
 }
+#ifdef _MSC_VER
+#  pragma optimize("", on)
+#endif
 
 void gpu_shader_create_info_exit()
 {