Revert "GL_ext_vulkan_glsl_relaxed extension support, and cross stage aware IO mapper"

Test/vk.relaxed.errorcheck.vert

@@ -1,15 +0,0 @@
-#version 460
-
-layout (location = 0) out vec4 io;
-
-// default uniforms will be gathered into a uniform block
-// final global block will merge uniforms from all linked files
-uniform vec2 a;     // declared in both stages with different type
-
-vec4 foo() {
-    return a.xyxy;
-}
-
-void main() {
-    io = foo();
-}