SPV: Implement Vulkan version of GLSL (KHR_vulkan_glsl).

Test/spv.atomic.comp

@@ -1,9 +1,11 @@
 #version 310 es
 
+#extension GL_ARB_gl_spirv : enable
+
 layout(binding = 0) uniform atomic_uint counter;
 
 layout(binding = 0, offset = 4) uniform atomic_uint countArr[4];
-uniform uint value;
+shared uint value;
 
 int arrX[gl_WorkGroupSize.x];
 int arrY[gl_WorkGroupSize.y];