New lint: Require # Safety section in pub unsafe fn docs

clippy_lints/src/lib.rs

@@ -708,6 +708,7 @@ pub fn register_plugins(reg: &mut rustc_driver::plugin::Registry<'_>, conf: &Con
         copies::IFS_SAME_COND,
         copies::IF_SAME_THEN_ELSE,
         derive::DERIVE_HASH_XOR_EQ,
+        doc::MISSING_SAFETY_DOC,
         double_comparison::DOUBLE_COMPARISONS,
         double_parens::DOUBLE_PARENS,
         drop_bounds::DROP_BOUNDS,
@@ -929,6 +930,7 @@ pub fn register_plugins(reg: &mut rustc_driver::plugin::Registry<'_>, conf: &Con
         block_in_if_condition::BLOCK_IN_IF_CONDITION_EXPR,
         block_in_if_condition::BLOCK_IN_IF_CONDITION_STMT,
         collapsible_if::COLLAPSIBLE_IF,
+        doc::MISSING_SAFETY_DOC,
         enum_variants::ENUM_VARIANT_NAMES,
         enum_variants::MODULE_INCEPTION,
         eq_op::OP_REF,