Web: Add sanity check test suite for smaller-footprint builds.

For the smallest builds, google tests will not be present, in
addition to a large number of tests not being capable of running.

Test/web.controlFlow.frag

@@ -0,0 +1,91 @@
+#version 310 es
+
+precision mediump float;
+precision highp int;
+
+int c, d;
+layout(location = 0) in highp float x;
+layout(location = 1) in vec4 bigColor;
+layout(location = 2) in vec4 BaseColor;
+layout(location = 3) in float f;
+
+layout(location = 4) flat in int Count;
+layout(location = 5) flat in uvec4 v4;
+
+layout(location = 0) out vec4 outColor;
+
+void main()
+{
+    float f;
+    int a[2];
+
+    switch(c)
+    {
+    }
+
+    switch (c) {      // a no-error normal switch
+    case 1:
+        f = sin(x);
+        break;
+    case 2:
+        switch (d) {
+        case 1:
+            f = x * x * x;
+            break;
+        case 2:
+            f = x * x;
+            break;
+        }
+        break;
+    default:
+        f = tan(x);
+    }
+
+    vec4 color = BaseColor;
+
+    for (int i = 0; i < Count; ++i) {
+        color += bigColor;
+    }
+
+    outColor = color;
+
+    float sum = 0.0;
+    for (int i = 0; i < 4; ++i)
+        sum += float(v4[i]);
+
+    vec4 tv4;
+
+    for (int i = 0; i < 4; ++i)
+        tv4[i] = float(v4[i] * 4u);
+
+    outColor += vec4(sum) + tv4;
+
+    vec4 r;
+    r.xyz = BaseColor.xyz;
+
+    for (int i = 0; i < Count; ++i)
+        r.w = f;
+
+    outColor.xyz += r.xyz;
+
+    for (int i = 0; i < 16; i += 4)
+        outColor *= f;
+
+    int i = 0;
+    int A, B, C, D;
+    while (i<10) {
+        A = 1;
+        if (i%2 == 0) {
+            B = 2;
+            continue;
+            C = 2;
+        }
+        if (i%5 == 0) {
+            B = 2;
+            break;
+            C = 2;
+        }
+        i++;
+    }
+    D = 3;
+}