Added gl_PerVertex out blocks to silence validation (Refs #277) [skip ci]

data/shaders/mesh/mesh.vert

@@ -21,6 +21,11 @@ layout (location = 2) out vec2 outUV;
 layout (location = 3) out vec3 outViewVec;
 layout (location = 4) out vec3 outLightVec;
 
+out gl_PerVertex
+{
+	vec4 gl_Position;
+};
+
 void main() 
 {
 	outNormal = inNormal;

data/shaders/pushconstants/lights.vert

@@ -25,6 +25,11 @@ layout (location = 2) out vec3 outColor;
 
 layout (location = 3) out vec4 outLightVec[lightCount];
 
+out gl_PerVertex
+{
+	vec4 gl_Position;
+};
+
 void main() 
 {
 	outNormal = inNormal;

data/shaders/scenerendering/scene.vert

@@ -22,6 +22,11 @@ layout (location = 2) out vec2 outUV;
 layout (location = 3) out vec3 outViewVec;
 layout (location = 4) out vec3 outLightVec;
 
+out gl_PerVertex
+{
+	vec4 gl_Position;
+};
+
 void main() 
 {
 	outNormal = inNormal;