Add tests for GL_NV_shader_noperspective_interpolation

Test/nvShaderNoperspectiveInterpolation.frag

@@ -0,0 +1,15 @@
+#version 300 es
+
+precision mediump float;
+
+noperspective in vec4 bad; // ERROR
+
+#extension GL_NV_shader_noperspective_interpolation : enable
+
+noperspective in vec4 color;
+
+out vec4 fragColor;
+
+void main() {
+    fragColor = color;
+}