update the since field to 1.12.0 for String AddAssign

oconnor663 · oconnor663 · commit cac58ab5b750 · 2016-07-18T14:00:35.000-04:00
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
@@ -1559,7 +1559,7 @@ impl<'a> Add<&'a str> for String {
     }
 }
 
-#[stable(feature = "rust1", since = "1.11.0")]
+#[stable(feature = "rust1", since = "1.12.0")]
 impl<'a> AddAssign<&'a str> for String {
     #[inline]
     fn add_assign(&mut self, other: &str) {

Original file line number	Diff line number	Diff line change
`@@ -1559,7 +1559,7 @@ impl<'a> Add<&'a str> for String {`
`1559`	`1559`	`}`
`1560`	`1560`	`}`
`1561`	`1561`
`1562`		`-#[stable(feature = "rust1", since = "1.11.0")]`
	`1562`	`+#[stable(feature = "rust1", since = "1.12.0")]`
`1563`	`1563`	`impl<'a> AddAssign<&'a str> for String {`
`1564`	`1564`	`#[inline]`
`1565`	`1565`	`fn add_assign(&mut self, other: &str) {`