Generic/DisallowLongArraySyntax: move an intentional parse error test

This commit moves an intentional parse error test to its own file. The
parse error test does not trigger
DisallowLongArraySyntaxSniff::process() as this sniff listen for
T_ARRAY and the `array` keyword without parentheses is tokenized by
PHPCS as T_STRING. Keeping the test as I'm not sure why it was
introduced and it might protect against regressions in the future if
things change in the tokenizer.

Author: rodrigoprimo

src/Standards/Generic/Tests/Arrays/DisallowLongArraySyntaxUnitTest.1.inc

@@ -10,7 +10,6 @@ $foo = array(
         3
        );
 $var = array/*comment*/(1,2,3);
-$var = array;
 
 function foo(array $array) {}
 

src/Standards/Generic/Tests/Arrays/DisallowLongArraySyntaxUnitTest.1.inc.fixed

@@ -10,7 +10,6 @@ $foo = [
         3
        ];
 $var = /*comment*/[1,2,3];
-$var = array;
 
 function foo(array $array) {}
 

src/Standards/Generic/Tests/Arrays/DisallowLongArraySyntaxUnitTest.3.inc

@@ -0,0 +1,7 @@
+<?php
+
+// Intentional parse error (long array syntax missing parentheses).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+$var = array;