Mark instanceof as left-associative

May not have been originally intended this way, but it's how the
language works right now, so specify it as such (#226).

Author: nikic

spec/10-expressions.md

@@ -1935,7 +1935,7 @@ instanceof-expression:
   instanceof-subject 'instanceof' class-type-designator
 
 instanceof-subject:
-  unary-expression
+  instanceof-expression
 -->
 
 <pre>
@@ -1944,17 +1944,13 @@ instanceof-subject:
    <i><a href="#grammar-instanceof-subject">instanceof-subject</a></i>   instanceof   <i><a href="#grammar-class-type-designator">class-type-designator</a></i>
 
 <i id="grammar-instanceof-subject">instanceof-subject:</i>
-   <i><a href="#grammar-unary-expression">unary-expression</a></i>
+   <i><a href="#grammar-instanceof-expression">instanceof-expression</a></i>
 </pre>
 
-**Constraints**
-
-The *unary-expression* in *instanceof-subject* must not be any form of literal.
-
 **Semantics**
 
 Operator `instanceof` returns `TRUE` if the value designated by
-*unary-expression* in *instanceof-subject* is an object having the type specified
+*instanceof-subject* is an object having the type specified
 by *class-type-designator*, is an object whose type is derived from that type,
 or is an object whose type implements the interface specified by *class-type-designator*.
 Otherwise, it returns `FALSE`.

spec/19-grammar.md

@@ -563,7 +563,7 @@ The grammar notation is described in [Grammars section](09-lexical-structure.md#
    <i><a href="#grammar-instanceof-subject">instanceof-subject</a></i>   instanceof   <i><a href="#grammar-class-type-designator">class-type-designator</a></i>
 
 <i id="grammar-instanceof-subject">instanceof-subject:</i>
-   <i><a href="#grammar-unary-expression">unary-expression</a></i>
+   <i><a href="#grammar-instanceof-expression">instanceof-expression</a></i>
 
 <i id="grammar-logical-NOT-expression">logical-NOT-expression:</i>
    <i><a href="#grammar-instanceof-expression">instanceof-expression</a></i>