Convert unsafety using the stable method and reuse mir::Safety

Author: spastorino

Diff for: compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -826,7 +826,7 @@ impl<'tcx> Stable<'tcx> for ty::FnSig<'tcx> {
     type T = stable_mir::ty::FnSig;
     fn stable(&self, tables: &mut Tables<'tcx>) -> Self::T {
         use rustc_target::spec::abi;
-        use stable_mir::ty::{Abi, FnSig, Unsafety};
+        use stable_mir::ty::{Abi, FnSig};
 
         FnSig {
             inputs_and_output: self
@@ -835,10 +835,7 @@ impl<'tcx> Stable<'tcx> for ty::FnSig<'tcx> {
                 .map(|ty| tables.intern_ty(ty))
                 .collect(),
             c_variadic: self.c_variadic,
-            unsafety: match self.unsafety {
-                hir::Unsafety::Normal => Unsafety::Normal,
-                hir::Unsafety::Unsafe => Unsafety::Unsafe,
-            },
+            unsafety: self.unsafety.stable(tables),
             abi: match self.abi {
                 abi::Abi::Rust => Abi::Rust,
                 abi::Abi::C { unwind } => Abi::C { unwind },

Diff for: compiler/rustc_smir/src/stable_mir/ty.rs

@@ -1,4 +1,4 @@
-use super::{mir::Mutability, with, DefId};
+use super::{mir::Mutability, mir::Safety, with, DefId};
 use crate::rustc_internal::Opaque;
 
 #[derive(Copy, Clone, Debug)]
@@ -140,16 +140,10 @@ pub type PolyFnSig = Binder<FnSig>;
 pub struct FnSig {
     pub inputs_and_output: Vec<Ty>,
     pub c_variadic: bool,
-    pub unsafety: Unsafety,
+    pub unsafety: Safety,
     pub abi: Abi,
 }
 
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub enum Unsafety {
-    Unsafe,
-    Normal,
-}
-
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub enum Abi {
     Rust,