Editorial: simplify definitions of Contains (#1519)

... after previous commit. Specifically, when code says:
```
1. If <something>, return *false*.
1. Return *false*.
```
we can drop the first step, because the result is `*false*` either way.

spec.html

@@ -12792,7 +12792,6 @@ <h1>Static Semantics: Contains</h1>
         </emu-note>
         <emu-grammar>LiteralPropertyName : IdentifierName</emu-grammar>
         <emu-alg>
-          1. If _symbol_ is a |ReservedWord|, return *false*.
           1. Return *false*.
         </emu-alg>
       </emu-clause>
@@ -13471,19 +13470,16 @@ <h1>Static Semantics: Contains</h1>
         <emu-grammar>MemberExpression : MemberExpression `.` IdentifierName</emu-grammar>
         <emu-alg>
           1. If |MemberExpression| Contains _symbol_ is *true*, return *true*.
-          1. If _symbol_ is a |ReservedWord|, return *false*.
           1. Return *false*.
         </emu-alg>
         <emu-grammar>SuperProperty : `super` `.` IdentifierName</emu-grammar>
         <emu-alg>
           1. If _symbol_ is the |ReservedWord| `super`, return *true*.
-          1. If _symbol_ is a |ReservedWord|, return *false*.
           1. Return *false*.
         </emu-alg>
         <emu-grammar>CallExpression : CallExpression `.` IdentifierName</emu-grammar>
         <emu-alg>
           1. If |CallExpression| Contains _symbol_ is *true*, return *true*.
-          1. If _symbol_ is a |ReservedWord|, return *false*.
           1. Return *false*.
         </emu-alg>
         <emu-grammar>OptionalChain : `?.` IdentifierName</emu-grammar>