Rollup merge of #21954 - jbcrail:fix-misspelled-comments, r=steveklabnik

 The spelling corrections were made in both documentation comments and
regular comments.

Author: Manishearth

src/doc/trpl/ownership.md

@@ -523,7 +523,7 @@ fn print<'a>(s: &'a str); // expanded
 fn debug(lvl: u32, s: &str); // elided
 fn debug<'a>(lvl: u32, s: &'a str); // expanded
 
-// In the preceeding example, `lvl` doesn't need a lifetime because it's not a
+// In the preceding example, `lvl` doesn't need a lifetime because it's not a
 // reference (`&`). Only things relating to references (such as a `struct`
 // which contains a reference) need lifetimes.
 

src/grammar/parser-lalr.y

@@ -1195,7 +1195,7 @@ maybe_stmts
 //
 // There are also two other expr subtypes: first, nonparen_expr
 // disallows exprs surrounded by parens (including tuple expressions),
-// this is neccesary for BOX (place) expressions, so a parens expr
+// this is necessary for BOX (place) expressions, so a parens expr
 // following the BOX is always parsed as the place. There is also
 // expr_norange used in index_expr, which disallows '..' in
 // expressions as that has special meaning inside of brackets.

src/liballoc/arc.rs

@@ -311,7 +311,7 @@ impl<T: Sync + Send> Drop for Arc<T> {
     ///
     ///     // stuff
     ///
-    ///     drop(five); // explict drop
+    ///     drop(five); // explicit drop
     /// }
     /// {
     ///     let five = Arc::new(5);
@@ -441,7 +441,7 @@ impl<T: Sync + Send> Drop for Weak<T> {
     ///
     ///     // stuff
     ///
-    ///     drop(weak_five); // explict drop
+    ///     drop(weak_five); // explicit drop
     /// }
     /// {
     ///     let five = Arc::new(5);

src/liballoc/rc.rs

@@ -383,7 +383,7 @@ impl<T> Drop for Rc<T> {
     ///
     ///     // stuff
     ///
-    ///     drop(five); // explict drop
+    ///     drop(five); // explicit drop
     /// }
     /// {
     ///     let five = Rc::new(5);
@@ -688,7 +688,7 @@ impl<T> Drop for Weak<T> {
     ///
     ///     // stuff
     ///
-    ///     drop(weak_five); // explict drop
+    ///     drop(weak_five); // explicit drop
     /// }
     /// {
     ///     let five = Rc::new(5);

src/libcollections/btree/node.rs

@@ -669,7 +669,7 @@ impl<'a, K: 'a, V: 'a> Handle<&'a mut Node<K, V>, handle::Edge, handle::Internal
 
 impl<K, V, NodeRef: Deref<Target=Node<K, V>>> Handle<NodeRef, handle::Edge, handle::Internal> {
     // This doesn't exist because there are no uses for it,
-    // but is fine to add, analagous to edge_mut.
+    // but is fine to add, analogous to edge_mut.
     //
     // /// Returns a reference to the edge pointed-to by this handle. This should not be
     // /// confused with `node`, which references the parent node of what is returned here.

src/libcore/iter.rs

@@ -260,7 +260,7 @@ pub trait IteratorExt: Iterator + Sized {
     }
 
     /// Creates an iterator that applies the predicate to each element returned
-    /// by this iterator. The only elements that will be yieled are those that
+    /// by this iterator. The only elements that will be yielded are those that
     /// make the predicate evaluate to `true`.
     ///
     /// # Examples

src/librustc/diagnostics.rs

@@ -14,9 +14,9 @@ register_long_diagnostics! {
     E0001: r##"
     This error suggests that the expression arm corresponding to the noted pattern
     will never be reached as for all possible values of the expression being matched,
-    one of the preceeding patterns will match.
+    one of the preceding patterns will match.
 
-    This means that perhaps some of the preceeding patterns are too general, this
+    This means that perhaps some of the preceding patterns are too general, this
     one is too specific or the ordering is incorrect.
 "##,
 

src/librustc/middle/traits/select.rs

@@ -775,7 +775,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                                      -> bool
     {
         // In general, it's a good idea to cache results, even
-        // ambigious ones, to save us some trouble later. But we have
+        // ambiguous ones, to save us some trouble later. But we have
         // to be careful not to cache results that could be
         // invalidated later by advances in inference. Normally, this
         // is not an issue, because any inference variables whose
@@ -1273,7 +1273,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     ///
     /// - The impl is conditional, in which case we may not have winnowed it out
     ///   because we don't know if the conditions apply, but the where clause is basically
-    ///   telling us taht there is some impl, though not necessarily the one we see.
+    ///   telling us that there is some impl, though not necessarily the one we see.
     ///
     /// In both cases we prefer to take the where clause, which is
     /// essentially harmless.  See issue #18453 for more details of

src/librustc/middle/ty.rs

@@ -2520,7 +2520,7 @@ impl FlagComputation {
     fn add_bound_computation(&mut self, computation: &FlagComputation) {
         self.add_flags(computation.flags);
 
-        // The types that contributed to `computation` occured within
+        // The types that contributed to `computation` occurred within
         // a region binder, so subtract one from the region depth
         // within when adding the depth to `self`.
         let depth = computation.depth;

src/librustc_borrowck/borrowck/doc.rs

@@ -142,7 +142,7 @@
 //! which contains an empty set of actions, still has a purpose---it
 //! prevents moves from `LV`. I chose not to make `MOVE` a fourth kind of
 //! action because that would imply that sometimes moves are permitted
-//! from restrictived values, which is not the case.
+//! from restricted values, which is not the case.
 //!
 //! #### Example
 //!