Fix: GPU: Implicit cast from int to bool in assert()

These are not valid in GLSL.

source/blender/draw/engines/eevee/shaders/eevee_closure_lib.glsl

@@ -51,7 +51,7 @@ float closure_evaluate_pdf(ClosureUndetermined cl, float3 L, float3 V, float thi
     case CLOSURE_NONE_ID:
       break;
   }
-  assert(0);
+  assert(false);
   return 0.0f;
 }
 
@@ -67,7 +67,7 @@ LightProbeRay bxdf_lightprobe_ray(ClosureUndetermined cl, float3 P, float3 V, fl
     case CLOSURE_BSDF_MICROFACET_GGX_REFLECTION_ID:
       break;
     case CLOSURE_NONE_ID:
-      assert(0);
+      assert(false);
       break;
   }
 
@@ -82,7 +82,7 @@ LightProbeRay bxdf_lightprobe_ray(ClosureUndetermined cl, float3 P, float3 V, fl
     case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
       return bxdf_ggx_lightprobe_transmission(to_closure_refraction(cl), V, thickness);
     case CLOSURE_NONE_ID:
-      assert(0);
+      assert(false);
       break;
   }
 

source/blender/draw/engines/eevee/shaders/eevee_deferred_combine_frag.glsl

@@ -98,7 +98,7 @@ void main()
         specular_indirect += closure_indirect_light;
         break;
       case CLOSURE_NONE_ID:
-        assert(0);
+        assert(false);
         break;
     }
 

source/blender/draw/engines/eevee/shaders/eevee_gbuffer_read_lib.glsl

@@ -151,7 +151,7 @@ struct Layers {
         return this->layer[2];
 #endif
     }
-    assert(0);
+    assert(false);
     return this->layer[0];
   }
 

source/blender/draw/engines/eevee/shaders/eevee_nodetree_lib.glsl

@@ -87,7 +87,7 @@ ClosureUndetermined g_closure_get(uchar i)
 #endif
   }
   /* Unreachable. */
-  assert(0);
+  assert(false);
   return g_closure_bins[0];
 }
 

source/blender/draw/engines/eevee/shaders/eevee_ray_generate_lib.glsl

@@ -39,7 +39,7 @@ BsdfSample ray_generate_direction(float2 noise, ClosureUndetermined cl, float3 V
     case CLOSURE_BSDF_DIFFUSE_ID:
       break;
     case CLOSURE_NONE_ID:
-      assert(0);
+      assert(false);
       break;
   }
 
@@ -73,7 +73,7 @@ BsdfSample ray_generate_direction(float2 noise, ClosureUndetermined cl, float3 V
       break;
     }
     case CLOSURE_NONE_ID:
-      assert(0);
+      assert(false);
       break;
   }
   samp.direction = tangent_to_world * float3(samp.direction);

source/blender/draw/engines/overlay/shaders/overlay_background_frag.glsl

@@ -84,7 +84,7 @@ void main()
       return;
     case BG_SOLID_CHECKER:
       /* Unreachable. */
-      assert(0);
+      assert(false);
       return;
   }