Shaders: reorder code for consistency.

It's InstancedObjectId and then PrimitiveId in the flags, so follow the
same order in the code also.

src/Magnum/Shaders/MeshVisualizer.frag

@@ -44,7 +44,7 @@
 #extension GL_NV_shader_noperspective_interpolation: require
 #endif
 
-#if (defined(WIREFRAME_RENDERING) || defined(PRIMITIVE_ID) || defined(PRIMITIVE_ID_FROM_VERTEX_ID) || defined(INSTANCED_OBJECT_ID)) && !defined(TBN_DIRECTION)
+#if (defined(WIREFRAME_RENDERING) || defined(INSTANCED_OBJECT_ID) || defined(PRIMITIVE_ID) || defined(PRIMITIVE_ID_FROM_VERTEX_ID)) && !defined(TBN_DIRECTION)
 #ifdef EXPLICIT_UNIFORM_LOCATION
 layout(location = 1)
 #endif
@@ -124,12 +124,12 @@ in lowp vec3 barycentric;
 #endif
 #endif
 
-#ifdef PRIMITIVE_ID_FROM_VERTEX_ID
-flat in highp uint interpolatedPrimitiveId;
-#endif
 #ifdef INSTANCED_OBJECT_ID
 flat in highp uint interpolatedInstanceObjectId;
 #endif
+#ifdef PRIMITIVE_ID_FROM_VERTEX_ID
+flat in highp uint interpolatedPrimitiveId;
+#endif
 
 #ifdef TBN_DIRECTION
 in lowp vec4 backgroundColor;

src/Magnum/Shaders/MeshVisualizer.geom

@@ -99,14 +99,14 @@ noperspective
 #endif
 out lowp vec3 dist;
 
-#ifdef PRIMITIVE_ID_FROM_VERTEX_ID
-flat in highp uint interpolatedVsPrimitiveId[];
-flat out highp uint interpolatedPrimitiveId;
-#endif
 #ifdef INSTANCED_OBJECT_ID
 flat in highp uint interpolatedVsInstanceObjectId[];
 flat out highp uint interpolatedInstanceObjectId;
 #endif
+#ifdef PRIMITIVE_ID_FROM_VERTEX_ID
+flat in highp uint interpolatedVsPrimitiveId[];
+flat out highp uint interpolatedPrimitiveId;
+#endif
 
 #if defined(TANGENT_DIRECTION) || defined(BITANGENT_DIRECTION) || defined(NORMAL_DIRECTION)
 out lowp vec4 backgroundColor;
@@ -167,6 +167,9 @@ void emitQuad(vec4 position, vec2 positionScreen, vec4 endpoint, vec2 endpointSc
 
 void main() {
     /* Passthrough for unchanged variables */
+    #ifdef INSTANCED_OBJECT_ID
+    interpolatedInstanceObjectId = interpolatedVsInstanceObjectId[0];
+    #endif
     #ifdef PRIMITIVE_ID_FROM_VERTEX_ID
     interpolatedPrimitiveId = interpolatedVsPrimitiveId[0];
     #elif defined(PRIMITIVE_ID)
@@ -176,9 +179,6 @@ void main() {
        also the TBN direction. */
     gl_PrimitiveID = gl_PrimitiveIDIn;
     #endif
-    #ifdef INSTANCED_OBJECT_ID
-    interpolatedInstanceObjectId = interpolatedVsInstanceObjectId[0];
-    #endif
 
     /* Screen position of each vertex */
     vec2 p[3];