Use one var/let/const per variable (fixup)

Fix few instances in generated code which I missed in the previous
commit.

See #443.

lib/compiler/passes/generate-js.js

@@ -718,20 +718,15 @@ function generateJS(ast, options) {
 
     parts.push('function peg$parse' + rule.name + '() {');
 
+    if (options.trace) {
+      parts.push('  var startPos = peg$currPos;');
+    }
+
     for (let i = 0; i <= stack.maxSp; i++) {
       stackVars[i] = s(i);
     }
 
-    if (options.trace) {
-      parts.push([
-        '  var ' + stackVars.join(', ') + ',',
-        '      startPos = peg$currPos;'
-      ].join('\n'));
-    } else {
-      parts.push(
-        '  var ' + stackVars.join(', ') + ';'
-      );
-    }
+    parts.push('  var ' + stackVars.join(', ') + ';');
 
     parts.push(indent2(generateRuleHeader(
       '"' + js.stringEscape(rule.name) + '"',
@@ -1248,12 +1243,6 @@ function generateJS(ast, options) {
       commonjs: function() {
         let parts          = [];
         let dependencyVars = Object.keys(options.dependencies);
-        let requires       = dependencyVars.map(
-              variable => variable
-                + ' = require("'
-                + js.stringEscape(options.dependencies[variable])
-                + '")'
-            );
 
         parts.push([
           generateGeneratedByComment(),
@@ -1262,8 +1251,14 @@ function generateJS(ast, options) {
           ''
         ].join('\n'));
 
-        if (requires.length > 0) {
-          parts.push('var ' + requires.join(', ') + ';');
+        if (dependencyVars.length > 0) {
+          dependencyVars.forEach(variable => {
+            parts.push('var ' + variable
+              + ' = require("'
+              + js.stringEscape(options.dependencies[variable])
+              + '");'
+            );
+          });
           parts.push('');
         }