Update CodeMirror to version 5.49.0 (#8381)

* Update CodeMirror to version 5.49.0

* Update CodeMirror versions in librejs and VERSIONS

public/vendor/plugins/codemirror/addon/fold/indent-fold.js

@@ -0,0 +1,48 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: https://codemirror.net/LICENSE
+
+(function(mod) {
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
+})(function(CodeMirror) {
+"use strict";
+
+function lineIndent(cm, lineNo) {
+  var text = cm.getLine(lineNo)
+  var spaceTo = text.search(/\S/)
+  if (spaceTo == -1 || /\bcomment\b/.test(cm.getTokenTypeAt(CodeMirror.Pos(lineNo, spaceTo + 1))))
+    return -1
+  return CodeMirror.countColumn(text, null, cm.getOption("tabSize"))
+}
+
+CodeMirror.registerHelper("fold", "indent", function(cm, start) {
+  var myIndent = lineIndent(cm, start.line)
+  if (myIndent < 0) return
+  var lastLineInFold = null
+
+  // Go through lines until we find a line that definitely doesn't belong in
+  // the block we're folding, or to the end.
+  for (var i = start.line + 1, end = cm.lastLine(); i <= end; ++i) {
+    var indent = lineIndent(cm, i)
+    if (indent == -1) {
+    } else if (indent > myIndent) {
+      // Lines with a greater indent are considered part of the block.
+      lastLineInFold = i;
+    } else {
+      // If this line has non-space, non-comment content, and is
+      // indented less or equal to the start line, it is the start of
+      // another block.
+      break;
+    }
+  }
+  if (lastLineInFold) return {
+    from: CodeMirror.Pos(start.line, cm.getLine(start.line).length),
+    to: CodeMirror.Pos(lastLineInFold, cm.getLine(lastLineInFold).length)
+  };
+});
+
+});