Normalize ++x to x++. (#5660)

There are only 10 instances of ++x in our codebase, compared with over 500 instances of x++.  The stlye guide has no opinion on which to use, nor do I.  But the lack of consistency was making regex searches for bugs more difficult.

generators/php/logic.js

@@ -33,7 +33,7 @@ Blockly.PHP['controls_if'] = function(block) {
     }
     code += (n > 0 ? ' else ' : '') +
         'if (' + conditionCode + ') {\n' + branchCode + '}';
-    ++n;
+    n++;
   } while (block.getInput('IF' + n));
 
   if (block.getInput('ELSE') || Blockly.PHP.STATEMENT_SUFFIX) {