Clarify that method calls can go on any type.

src/expressions/method-call-expr.md

@@ -2,9 +2,9 @@
 
 A _method call_ consists of an expression (the *receiver*) followed by a single
 dot, an [identifier], and a parenthesized expression-list. Method calls are
-resolved to methods on specific traits, either statically dispatching to a
-method if the exact `self`-type of the left-hand-side is known, or dynamically
-dispatching if the left-hand-side expression is an indirect [trait
+resolved to associated methods of specific types, either statically dispatching
+to a method if the exact `self`-type of the left-hand-side is known, or
+dynamically dispatching if the left-hand-side expression is an indirect [trait
 object](types.html#trait-objects).
 
 ```rust