SPV: Implement Vulkan version of GLSL (KHR_vulkan_glsl).

Test/spv.sparseTexture.frag

@@ -16,11 +16,11 @@ uniform isampler2DArray         is2DArray;
 uniform usamplerCubeArray       usCubeArray;
 uniform usampler2DRect          us2DRect;
 
-uniform vec2 c2;
-uniform vec3 c3;
-uniform vec4 c4;
+in vec2 c2;
+in vec3 c3;
+in vec4 c4;
 
-uniform ivec2 offsets[4];
+in flat ivec2 offsets[4];
 
 out vec4 outColor;