message: Fix mingw searching
  The windows mingw scan part was broke.
  This modification removes some dead code and fix the scanning.
diff: @@ -657,26 +657,8 @@ export interface KitScanOptions {
  * @returns A list of Kits.
  */
  export async function scanForKits(opt?: KitScanOptions) {
  - if (opt === undefined) {
  - opt = {};
  - }
  - const in_scan_dirs = opt.scanDirs;
  - let scan_dirs: string[];
  - if (in_scan_dirs !== undefined) {
  - scan_dirs = in_scan_dirs;
  - } else {
  - const env_path = process.env['PATH'] || '';
  - const isWin32 = process.platform === 'win32';
  - const sep = isWin32 ? ';' : ':';
  - let env_elems = env_path.split(sep);
  - if (env_elems.length === 1 && env_elems[0] === '') {
  - env_elems = [];
  - }
  - scan_dirs = env_elems;
  - }
  - if (opt.minGWSearchDirs) {
  - scan_dirs = scan_dirs.concat(convertMingwDirsToSearchPaths(opt.minGWSearchDirs));
  - }
  + const kit_options = opt ? opt : {};
  +
  log.debug('Scanning for Kits on system');
  const prog = {
  location: vscode.ProgressLocation.Notification,
  @@ -693,13 +675,20 @@ export async function scanForKits(opt?: KitScanOptions) {
  scanPaths = scanPaths.concat(pathvar.split(sep));
  }
  - if (scanPaths) {
  + if (kit_options) {
  // Search them all in parallel
  let prs = [] as Promise<Kit[]>[];
  const compiler_kits = scanPaths.map(path_el => scanDirForCompilerKits(path_el, pr));
  prs = prs.concat(compiler_kits);
  if (isWin32) {
  const vs_kits = scanForVSKits(pr);
  +
  + if (kit_options.minGWSearchDirs) {
  + const mingw_path = scanPaths.concat(convertMingwDirsToSearchPaths(kit_options.minGWSearchDirs));
  + const mingw_kits_prs = mingw_path.map(path_el => scanDirForCompilerKits(path_el, pr));
  + prs = prs.concat(mingw_kits_prs);
  + }
  +
  const clang_cl_path = ['C:\\Program Files (x86)\\LLVM\\bin', 'C:\\Program Files\\LLVM\\bin', ...scanPaths];
  const clang_cl_kits = await scanForClangCLKits(clang_cl_path);
  prs.push(vs_kits);
  