Backport to Rust 1.15

* Avoid using some missing From impls
* Manually re-order fields

Author: SimonSapin

src/compact_cow_str.rs

@@ -105,7 +105,7 @@ impl<'a> Clone for CompactCowStr<'a> {
         if self.is_borrowed() {
             CompactCowStr { ..*self }
         } else {
-            Self::from(Box::from(&**self))
+            Self::from(String::from(&**self).into_boxed_str())
         }
     }
 }
@@ -142,7 +142,7 @@ impl<'a> From<CompactCowStr<'a>> for Cow<'a, str> {
             if is_borrowed {
                 Cow::Borrowed(&*raw)
             } else {
-                Cow::Owned(String::from(Box::from_raw(raw as *mut str)))
+                Cow::Owned(Box::from_raw(raw as *mut str).into_string())
             }
         }
     }

src/tokenizer.rs

@@ -60,17 +60,17 @@ pub enum Token<'a> {
 
     /// A [`<dimension-token>`](https://drafts.csswg.org/css-syntax/#dimension-token-diagram)
     Dimension {
+        /// Whether the number had a `+` or `-` sign.
+        ///
+        /// This is used is some cases like the <An+B> micro syntax. (See the `parse_nth` function.)
+        has_sign: bool,
+
         /// The value as a float
         value: f32,
 
         /// If the origin source did not include a fractional part, the value as an integer.
         int_value: Option<i32>,
 
-        /// Whether the number had a `+` or `-` sign.
-        ///
-        /// This is used is some cases like the <An+B> micro syntax. (See the `parse_nth` function.)
-        has_sign: bool,
-
         /// The unit, e.g. "px" in `12px`
         unit: CompactCowStr<'a>
     },