Move cast_ref_to_mut list to correctness group

Author: KamilaBorowska

clippy_lints/src/lib.rs

@@ -759,6 +759,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
         types::BOX_VEC,
         types::CAST_LOSSLESS,
         types::CAST_PTR_ALIGNMENT,
+        types::CAST_REF_TO_MUT,
         types::CHAR_LIT_AS_U8,
         types::FN_TO_NUMERIC_CAST,
         types::FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
@@ -990,6 +991,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
         transmute::WRONG_TRANSMUTE,
         types::ABSURD_EXTREME_COMPARISONS,
         types::CAST_PTR_ALIGNMENT,
+        types::CAST_REF_TO_MUT,
         types::UNIT_CMP,
         unicode::ZERO_WIDTH_SPACE,
         unused_io_amount::UNUSED_IO_AMOUNT,
@@ -1027,7 +1029,6 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
         mutex_atomic::MUTEX_INTEGER,
         needless_borrow::NEEDLESS_BORROW,
         redundant_clone::REDUNDANT_CLONE,
-        types::CAST_REF_TO_MUT,
         unwrap::PANICKING_UNWRAP,
         unwrap::UNNECESSARY_UNWRAP,
     ]);

clippy_lints/src/types.rs

@@ -2269,7 +2269,7 @@ impl<'a, 'b, 'tcx: 'a + 'b> Visitor<'tcx> for ImplicitHasherConstructorVisitor<'
 /// ```
 declare_clippy_lint! {
     pub CAST_REF_TO_MUT,
-    nursery,
+    correctness,
     "a cast of reference to a mutable pointer"
 }