Fix interpolant ES error

The restriction of no swizzling and no struct fields as an interpolant
were not being checked when using the ES profile.

Fixes #3277.

Test/glsl.interpOp.error.frag

@@ -0,0 +1,73 @@
+#version 320 es
+
+struct S
+{
+    highp float a;
+    highp float b;
+};
+layout(location = 0) in S v_var;
+
+layout(location = 2) in highp float v;
+
+struct S0 {
+    highp vec4 s_v;
+};
+
+layout(location = 3) in FIn {
+    highp float x;
+    highp vec4 xyz[1];
+    S0 s0;
+};
+
+layout(location = 7) in highp float z[1];
+
+layout(location = 8) in highp vec4 w;
+
+layout(location = 0) out mediump vec4 fragColor;
+void main (void)
+{
+    // Centroid
+    {
+        // valid
+        fragColor = vec4(interpolateAtCentroid(v));
+        fragColor = vec4(interpolateAtCentroid(x));
+        fragColor = vec4(interpolateAtCentroid(z[0]));
+        fragColor = interpolateAtCentroid(w);
+        fragColor = interpolateAtCentroid(xyz[0]);
+
+        //// invalid
+        fragColor = vec4(interpolateAtCentroid(v_var.a));
+        fragColor = vec4(interpolateAtCentroid(w.x));
+        fragColor = vec4(interpolateAtCentroid(s0.s_v));
+    }
+
+    // Sample
+    {
+        // valid
+        fragColor = vec4(interpolateAtSample(v, 0));
+        fragColor = vec4(interpolateAtSample(x, 0));
+        fragColor = vec4(interpolateAtSample(z[0], 0));
+        fragColor = interpolateAtSample(w, 0);
+        fragColor = interpolateAtSample(xyz[0], 0);
+
+        // invalid
+        fragColor = vec4(interpolateAtSample(v_var.a, 0));
+        fragColor = vec4(interpolateAtSample(w.x, 0));
+        fragColor = vec4(interpolateAtSample(s0.s_v, 0));
+    }
+
+    // Offset
+    {
+        // valid
+        fragColor = vec4(interpolateAtOffset(v,    vec2(0)));
+        fragColor = vec4(interpolateAtOffset(x,    vec2(0)));
+        fragColor = vec4(interpolateAtOffset(z[0], vec2(0)));
+        fragColor = interpolateAtOffset(w,         vec2(0));
+        fragColor = interpolateAtOffset(xyz[0],    vec2(0));
+
+        // invalid
+        fragColor = vec4(interpolateAtOffset(v_var.a, vec2(0)));
+        fragColor = vec4(interpolateAtOffset(w.x,     vec2(0)));
+        fragColor = vec4(interpolateAtOffset(s0.s_v, vec2(0)));
+    }
+}