Port #[rustc_layout_scalar_valid_range_start/end] to the new attribute parsing infrastructure

Signed-off-by: Jonathan Brouwer <jonathantbrouwer@gmail.com>

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -35,6 +35,7 @@ pub(crate) mod lint_helpers;
 pub(crate) mod loop_match;
 pub(crate) mod must_use;
 pub(crate) mod repr;
+pub(crate) mod rustc_internal;
 pub(crate) mod semantics;
 pub(crate) mod stability;
 pub(crate) mod traits;