Rollup merge of #28788 - tsurai:master, r=bluss

Please correct me if I confused something but the documentation for ```into_ptr``` and ```into_raw``` of ```CString``` seem to be swapped as the docs for ```into_ptr``` mentions ```into_raw``` and vice versa.

Update: I actually meant ```into_ptr``` and ```into_raw``` NOT ```from_*```

Author: steveklabnik

src/libstd/ffi/c_str.rs

@@ -206,7 +206,7 @@ impl CString {
     /// Retakes ownership of a CString that was transferred to C.
     ///
     /// The only appropriate argument is a pointer obtained by calling
-    /// `into_ptr`. The length of the string will be recalculated
+    /// `into_raw`. The length of the string will be recalculated
     /// using the pointer.
     #[unstable(feature = "cstr_memory2", reason = "recently added",
                issue = "27769")]
@@ -245,11 +245,11 @@ impl CString {
     /// Transfers ownership of the string to a C caller.
     ///
     /// The pointer must be returned to Rust and reconstituted using
-    /// `from_ptr` to be properly deallocated. Specifically, one
+    /// `from_raw` to be properly deallocated. Specifically, one
     /// should *not* use the standard C `free` function to deallocate
     /// this string.
     ///
-    /// Failure to call `from_ptr` will lead to a memory leak.
+    /// Failure to call `from_raw` will lead to a memory leak.
     #[stable(feature = "cstr_memory", since = "1.4.0")]
     pub fn into_raw(self) -> *mut libc::c_char {
         Box::into_raw(self.inner) as *mut libc::c_char