Hack in a fix for the Span hash_stable regression

Author: saethlin

compiler/rustc_span/src/lib.rs

@@ -1886,6 +1886,30 @@ macro_rules! impl_pos {
             $(#[$attr])*
             $vis struct $ident($inner_vis $inner_ty);
 
+            impl ::std::cmp::Ord for $ident {
+                #[inline(always)]
+                fn cmp(&self, other: &Self) -> ::std::cmp::Ordering {
+                    self.0.cmp(&other.0)
+                }
+            }
+
+            impl ::std::cmp::PartialOrd for $ident {
+                #[inline(always)]
+                fn partial_cmp(&self, other: &Self) -> Option<::std::cmp::Ordering> {
+                    self.0.partial_cmp(&other.0)
+                }
+
+                #[inline(always)]
+                fn lt(&self, other: &Self) -> bool {
+                    self.0.lt(&other.0)
+                }
+
+                #[inline(always)]
+                fn le(&self, other: &Self) -> bool {
+                    self.0.le(&other.0)
+                }
+             }
+
             impl Pos for $ident {
                 #[inline(always)]
                 fn from_usize(n: usize) -> $ident {
@@ -1933,15 +1957,15 @@ impl_pos! {
     /// A byte offset.
     ///
     /// Keep this small (currently 32-bits), as AST contains a lot of them.
-    #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
+    #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
     pub struct BytePos(pub u32);
 
     /// A character offset.
     ///
     /// Because of multibyte UTF-8 characters, a byte offset
     /// is not equivalent to a character offset. The [`SourceMap`] will convert [`BytePos`]
     /// values to `CharPos` values as necessary.
-    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug)]
+    #[derive(Clone, Copy, PartialEq, Eq, Debug)]
     pub struct CharPos(pub usize);
 }