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.basic.vert

@@ -0,0 +1,15 @@
+#version 310 es
+
+layout(location = 2) in vec4 inv4;
+layout(location = 1) out vec4 outv4;
+
+layout(binding = 3) uniform uBlock {
+    vec4 a;
+    ivec4 b;
+    uvec4 c;
+} uInst;
+
+void main()
+{
+    outv4 = normalize(inv4) * uInst.a * vec4(uInst.b) * vec4(uInst.c);
+}