Move hb_stable_sort to hb-dsalgs.hh

Also, include hb-dsalgs.hh from end of hb-pricate.hh

src/hb-dsalgs.hh

diff --git a/src/hb-dsalgs.hh b/src/hb-dsalgs.hh
index 9586871..68b1fd1 100644
--- a/src/hb-dsalgs.hh
+++ b/src/hb-dsalgs.hh
@@ -158,4 +158,55 @@
     sort_r_simple(base, nel, width, compar, arg);
 }
 
+
+template <typename T, typename T2> static inline void
+hb_stable_sort (T *array, unsigned int len, int(*compar)(const T *, const T *), T2 *array2)
+{
+  for (unsigned int i = 1; i < len; i++)
+  {
+    unsigned int j = i;
+    while (j && compar (&array[j - 1], &array[i]) > 0)
+      j--;
+    if (i == j)
+      continue;
+    /* Move item i to occupy place for item j, shift what's in between. */
+    {
+      T t = array[i];
+      memmove (&array[j + 1], &array[j], (i - j) * sizeof (T));
+      array[j] = t;
+    }
+    if (array2)
+    {
+      T2 t = array2[i];
+      memmove (&array2[j + 1], &array2[j], (i - j) * sizeof (T2));
+      array2[j] = t;
+    }
+  }
+}
+
+template <typename T> static inline void
+hb_stable_sort (T *array, unsigned int len, int(*compar)(const T *, const T *))
+{
+  hb_stable_sort (array, len, compar, (int *) nullptr);
+}
+
+static inline hb_bool_t
+hb_codepoint_parse (const char *s, unsigned int len, int base, hb_codepoint_t *out)
+{
+  /* Pain because we don't know whether s is nul-terminated. */
+  char buf[64];
+  len = MIN (ARRAY_LENGTH (buf) - 1, len);
+  strncpy (buf, s, len);
+  buf[len] = '\0';
+
+  char *end;
+  errno = 0;
+  unsigned long v = strtoul (buf, &end, base);
+  if (errno) return false;
+  if (*end) return false;
+  *out = v;
+  return true;
+}
+
+
 #endif /* HB_DSALGS_HH */