SPV: Prevent issue #415 with better semantic checking.

Test/baseResults/vulkan.frag.out

@@ -33,7 +33,12 @@ ERROR: 0:67: 'uniform' : no qualifiers allowed for function return
 ERROR: 0:69: 'non-opaque uniforms outside a block' : not allowed when using GLSL for Vulkan 
 ERROR: 0:73: 'texture' : no matching overloaded function found 
 ERROR: 0:74: 'imageStore' : no matching overloaded function found 
-ERROR: 33 compilation errors.  No code generated.
+ERROR: 0:91: 'call argument' : sampler constructor must appear at point of use 
+ERROR: 0:92: 'call argument' : sampler constructor must appear at point of use 
+ERROR: 0:93: ',' : sampler constructor must appear at point of use 
+ERROR: 0:94: ':' :  wrong operand types: no operation ':' exists that takes a left-hand operand of type 'temp sampler2D' and a right operand of type 'temp sampler2D' (or there is no acceptable conversion)
+ERROR: 0:94: 'call argument' : sampler constructor must appear at point of use 
+ERROR: 38 compilation errors.  No code generated.
 
 
 

Test/vulkan.frag

@@ -72,4 +72,24 @@ void fooTex()
 {
     texture(t2d, vec2(1.0));                 // ERROR, need a sampler, not a pure texture
     imageStore(t2d, ivec2(4, 5), vec4(1.2)); // ERROR, need an image, not a pure texture
-}
+}
+
+precision highp float;
+
+layout(location=0) in vec2 vTexCoord;
+layout(location=0) out vec4 FragColor;
+
+vec4 userTexture(mediump sampler2D samp, vec2 coord)
+{
+    return texture(samp, coord);
+}
+
+bool cond;
+
+void callUserTexture()
+{
+    userTexture(sampler2D(t2d,s), vTexCoord);                            // ERROR, not point of use
+    userTexture((sampler2D(t2d,s)), vTexCoord);                          // ERROR, not point of use
+    userTexture((sampler2D(t2d,s), sampler2D(t2d,s)), vTexCoord);        // ERROR, not point of use
+    userTexture(cond ? sampler2D(t2d,s) : sampler2D(t2d,s), vTexCoord);  // ERROR, no ?:, not point of use
+}