Revert "glsl: fix xfb_offset unsized array validation"

This reverts commit aac90ba292.

The commit caused a regression in:
piglit.spec.glsl-1_50.compiler.gs-input-nonarray-named-block.geom

Also the CTS test it was meant to fix seems like it may be bogus.

Cc: "12.0" <mesa-stable@lists.freedesktop.org>

src/compiler/glsl/link_varyings.cpp

@@ -40,6 +40,29 @@
 #include "program.h"
 
 
+/**
+ * Get the varying type stripped of the outermost array if we're processing
+ * a stage whose varyings are arrays indexed by a vertex number (such as
+ * geometry shader inputs).
+ */
+static const glsl_type *
+get_varying_type(const ir_variable *var, gl_shader_stage stage)
+{
+   const glsl_type *type = var->type;
+
+   if (!var->data.patch &&
+       ((var->data.mode == ir_var_shader_out &&
+         stage == MESA_SHADER_TESS_CTRL) ||
+        (var->data.mode == ir_var_shader_in &&
+         (stage == MESA_SHADER_TESS_CTRL || stage == MESA_SHADER_TESS_EVAL ||
+          stage == MESA_SHADER_GEOMETRY)))) {
+      assert(type->is_array());
+      type = type->fields.array;
+   }
+
+   return type;
+}
+
 static void
 create_xfb_varying_names(void *mem_ctx, const glsl_type *t, char **name,
                          size_t name_length, unsigned *count,