Fix csv regex undefined matching group

Ref: codemirror#5374 (comment)

Author: Yukaii

addon/mode/simple.js

@@ -94,7 +94,7 @@
 
   function tokenFunction(states, config) {
     return function(stream, state) {
-      if (state.pending && state.pending.length > 0) {
+      if (state.pending) {
         var pend = state.pending.shift();
         if (state.pending.length == 0) state.pending = null;
         stream.pos += pend.text.length;

mode/csv/csv.js

@@ -10,7 +10,7 @@
   CodeMirror.defineSimpleMode('csv', {
     start: [
       {
-        regex: /((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?((?: *\"(?:[^\"]*\"\")*[^\"]*\" *(?:,|$))|(?:[^,]*(?:,|$)))?/,
+        regex: /((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)((?: *"(?:[^"]*"")*[^"]*" *(?:,|$))|(?:[^,]*(?:,|$))|)/,
         token: [
           "variable",
           "variable-2",