Add support for GL_EXT_samplerless_texture_functions

Test/samplerlessTextureFunctions.frag

@@ -0,0 +1,46 @@
+#version 450 core
+
+layout(binding = 1) uniform texture2D tex2D;
+layout(binding = 1) uniform texture2DMS texMS;
+layout(binding = 0) uniform textureBuffer buf;
+
+void testBad()
+{
+    vec4 tex2DFetch = texelFetch(tex2D, ivec2(0, 0), 0);
+    vec4 texMSFetch = texelFetch(texMS, ivec2(0, 0), 0);
+
+    // Allowed by KHR_vulkan_glsl without the extension. All others should
+    // error.
+    vec4 bufFetch = texelFetch(buf, 0);
+
+    vec4 tex2DFetchOffset = texelFetchOffset(tex2D, ivec2(0, 0), 0, ivec2(0, 0));
+
+    ivec2 tex2DSize = textureSize(tex2D, 0);
+    ivec2 texMSSize = textureSize(texMS);
+    int bufSize = textureSize(buf);
+
+    int tex2DLevels = textureQueryLevels(tex2D);
+
+    int texMSSamples = textureSamples(texMS);
+}
+
+#extension GL_EXT_samplerless_texture_functions : enable
+
+void main()
+{
+    // These should all succeed.
+
+    vec4 tex2DFetch = texelFetch(tex2D, ivec2(0, 0), 0);
+    vec4 texMSFetch = texelFetch(texMS, ivec2(0, 0), 0);
+    vec4 bufFetch = texelFetch(buf, 0);
+
+    vec4 tex2DFetchOffset = texelFetchOffset(tex2D, ivec2(0, 0), 0, ivec2(0, 0));
+
+    ivec2 tex2DSize = textureSize(tex2D, 0);
+    ivec2 texMSSize = textureSize(texMS);
+    int bufSize = textureSize(buf);
+
+    int tex2DLevels = textureQueryLevels(tex2D);
+
+    int texMSSamples = textureSamples(texMS);
+}