message: Add log messages when errors occur with backward SyncTeX.
diff: @@ -296,14 +296,22 @@ export class Locator {
  // see http://tex.stackexchange.com/questions/25578/why-is-synctex-in-tl-2011-so-fussy-about-filenames.
  // We compare the return of symlink with the files list in the texFileTree and try to pickup the correct one.
  for (const ed in this.extension.manager.cachedContent) {
  + try {
  if (fs.realpathSync(record.input) === fs.realpathSync(ed)) {
  record.input = ed
  break
  }
  + } catch(e) {
  + this.extension.logger.addLogMessage(`Error while calling fs.realpathSync for ${record.input} and ${ed}`)
  + }
  }
  const filePath = path.resolve(record.input)
  this.extension.logger.addLogMessage(`SyncTeX to file ${filePath}`)
  + if (!fs.existsSync(filePath)) {
  + this.extension.logger.addLogMessage(`Not found: ${filePath}`)
  + return
  + }
  vscode.workspace.openTextDocument(filePath).then((doc) => {
  let viewColumn: vscode.ViewColumn | undefined = undefined
  for (let index = 0; index < vscode.window.visibleTextEditors.length; index++) {
  