Add a builtin_type_shadow lint

clippy_lints/src/utils/constants.rs

@@ -0,0 +1,21 @@
+//! This module contains some useful constants.
+
+#![deny(missing_docs_in_private_items)]
+
+/// List of the built-in types names.
+///
+/// See also [the reference][reference-types] for a list of such types.
+///
+/// [reference-types]: https://doc.rust-lang.org/reference.html#types
+pub const BUILTIN_TYPES: &'static [&'static str] = &[
+    "i8", "u8",
+    "i16", "u16",
+    "i32", "u32",
+    "i64", "u64",
+    "isize", "usize",
+    "f32",
+    "f64",
+    "bool",
+    "str",
+    "char",
+];

clippy_lints/src/utils/mod.rs

@@ -22,6 +22,7 @@ use syntax::ptr::P;
 pub mod cargo;
 pub mod comparisons;
 pub mod conf;
+pub mod constants;
 mod hir;
 pub mod paths;
 pub mod sugg;