Remove outdated comment.

Author: cjgillot

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -565,9 +565,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         // with #[rustc_inherit_overflow_checks] and inlined from
         // another crate (mostly core::num generic/#[inline] fns),
         // while the current crate doesn't use overflow checks.
-        // NOTE: Unlike binops, negation doesn't have its own
-        // checked operation, just a comparison with the minimum
-        // value, so we have to check for the assert message.
         if !bx.cx().check_overflow() {
             let unchecked_overflow = match msg {
                 AssertKind::OverflowNeg(..) => true,