Ensure test file YAML blocks don't have a trailing space. (#2018)

test/language/statements/for-of/array.js

@@ -5,7 +5,7 @@
   description: >
       Array instances should be able to be traversed using a `for...of` loop.
   es6id: 13.6.4
- ---*/
+---*/
 
 var array = [0, 'a', true, false, null, /* hole */, undefined, NaN];
 var i = 0;

test/language/statements/labeled/value-yield-non-strict.js

@@ -7,6 +7,6 @@
       used as a label.
   es6id: 12.1.1
   flags: [noStrict]
- ---*/
+---*/
 
 yield: 1;

test/language/statements/labeled/value-yield-strict.js

@@ -10,7 +10,7 @@
     phase: parse
     type: SyntaxError
   flags: [onlyStrict]
- ---*/
+---*/
 
 $DONOTEVALUATE();