perf(completion): use one call to globpath() for .vim and .lua #21942

Test using the following test script (timings with ASAN):

    let start = reltime()
    for i in range(100)
      call getcompletion('', 'filetype')
    endfor
    echomsg reltimefloat(reltime(start))

Without this PR: 3.251825 seconds
With this PR: 2.747285 seconds

src/nvim/runtime.c

@@ -1190,56 +1190,46 @@ int ExpandRTDir(char *pat, int flags, int *num_file, char ***file, char *dirname
  garray_T ga;
  ga_init(&ga, (int)sizeof(char *), 10);
 
- // TODO(bfredl): this is bullshit, exandpath should not reinvent path logic.
+ // TODO(bfredl): this is bullshit, expandpath should not reinvent path logic.
  for (int i = 0; dirnames[i] != NULL; i++) {
- size_t size = strlen(dirnames[i]) + pat_len + 7;
+ size_t size = strlen(dirnames[i]) + pat_len + 16;
  char *s = xmalloc(size);
- snprintf(s, size, "%s/%s*.vim", dirnames[i], pat);
- globpath(p_rtp, s, &ga, 0);
- snprintf(s, size, "%s/%s*.lua", dirnames[i], pat);
+ snprintf(s, size, "%s/%s*.\\(vim\\|lua\\)", dirnames[i], pat);
  globpath(p_rtp, s, &ga, 0);
  xfree(s);
  }
 
  if (flags & DIP_START) {
  for (int i = 0; dirnames[i] != NULL; i++) {
- size_t size = strlen(dirnames[i]) + pat_len + 22;
+ size_t size = strlen(dirnames[i]) + pat_len + 31;
  char *s = xmalloc(size);
- snprintf(s, size, "pack/*/start/*/%s/%s*.vim", dirnames[i], pat); // NOLINT
- globpath(p_pp, s, &ga, 0);
- snprintf(s, size, "pack/*/start/*/%s/%s*.lua", dirnames[i], pat); // NOLINT
+ snprintf(s, size, "pack/*/start/*/%s/%s*.\\(vim\\|lua\\)", dirnames[i], pat); // NOLINT
  globpath(p_pp, s, &ga, 0);
  xfree(s);
  }
 
  for (int i = 0; dirnames[i] != NULL; i++) {
- size_t size = strlen(dirnames[i]) + pat_len + 22;
+ size_t size = strlen(dirnames[i]) + pat_len + 31;
  char *s = xmalloc(size);
- snprintf(s, size, "start/*/%s/%s*.vim", dirnames[i], pat); // NOLINT
- globpath(p_pp, s, &ga, 0);
- snprintf(s, size, "start/*/%s/%s*.lua", dirnames[i], pat); // NOLINT
+ snprintf(s, size, "start/*/%s/%s*.\\(vim\\|lua\\)", dirnames[i], pat); // NOLINT
  globpath(p_pp, s, &ga, 0);
  xfree(s);
  }
  }
 
  if (flags & DIP_OPT) {
  for (int i = 0; dirnames[i] != NULL; i++) {
- size_t size = strlen(dirnames[i]) + pat_len + 20;
+ size_t size = strlen(dirnames[i]) + pat_len + 29;
  char *s = xmalloc(size);
- snprintf(s, size, "pack/*/opt/*/%s/%s*.vim", dirnames[i], pat); // NOLINT
- globpath(p_pp, s, &ga, 0);
- snprintf(s, size, "pack/*/opt/*/%s/%s*.lua", dirnames[i], pat); // NOLINT
+ snprintf(s, size, "pack/*/opt/*/%s/%s*.\\(vim\\|lua\\)", dirnames[i], pat); // NOLINT
  globpath(p_pp, s, &ga, 0);
  xfree(s);
  }
 
  for (int i = 0; dirnames[i] != NULL; i++) {
- size_t size = strlen(dirnames[i]) + pat_len + 20;
+ size_t size = strlen(dirnames[i]) + pat_len + 29;
  char *s = xmalloc(size);
- snprintf(s, size, "opt/*/%s/%s*.vim", dirnames[i], pat); // NOLINT
- globpath(p_pp, s, &ga, 0);
- snprintf(s, size, "opt/*/%s/%s*.lua", dirnames[i], pat); // NOLINT
+ snprintf(s, size, "opt/*/%s/%s*.\\(vim\\|lua\\)", dirnames[i], pat); // NOLINT
  globpath(p_pp, s, &ga, 0);
  xfree(s);
  }