Bug#55980 Character sets: supplementary character _bin ordering is wrong

Post-fix:
  Reverting the "utf16_bin did not sort supplementary characters
  between U+D700 and U+E000" part. We'll use code-point order.

Committing on behalf of Alexander Barkov.

mysql-test/r/ctype_utf16.result

@@ -625,16 +625,16 @@ INSERT INTO t1 VALUES (_utf8mb4 0xCE85),(_utf8mb4 0xF4808080);
 SELECT HEX(a), HEX(CONVERT(a USING utf8mb4)) FROM t1 ORDER BY a;
 HEX(a)	HEX(CONVERT(a USING utf8mb4))
 0385	CE85
+FF9D	EFBE9D
 D800DF84	F0908E84
 DBC0DC00	F4808080
-FF9D	EFBE9D
 ALTER TABLE t1 ADD KEY(a);
 SELECT HEX(a), HEX(CONVERT(a USING utf8mb4)) FROM t1 ORDER BY a;
 HEX(a)	HEX(CONVERT(a USING utf8mb4))
 0385	CE85
+FF9D	EFBE9D
 D800DF84	F0908E84
 DBC0DC00	F4808080
-FF9D	EFBE9D
 DROP TABLE IF EXISTS t1;
 select @@collation_connection;
 @@collation_connection

strings/ctype-ucs2.c

@@ -1463,7 +1463,7 @@ my_strnncoll_utf16_bin(CHARSET_INFO *cs,
     }
     if (s_wc != t_wc)
     {
-      return  my_bincmp(s, s + s_res, t, t + t_res);
+      return s_wc > t_wc ? 1 : -1;
     }
 
     s+= s_res;
@@ -1503,7 +1503,7 @@ my_strnncollsp_utf16_bin(CHARSET_INFO *cs,
 
     if (s_wc != t_wc)
     {
-      return my_bincmp(s, s + s_res, t, t + t_res);
+      return s_wc > t_wc ? 1 : -1;
     }
 
     s+= s_res;

strings/ctype-utf8.c

@@ -1967,17 +1967,6 @@ my_strnxfrm_unicode_full_bin(CHARSET_INFO *cs,
     if ((res= cs->cset->mb_wc(cs, &wc, src, se)) <= 0)
       break;
     src+= res;
-    if (cs->mbminlen == 2) /* utf16_bin */
-    {
-      /*
-        Reorder code points to weights as follows:
-        U+0000..U+D7FF    -> [00][00][00]..[00][D7][FF] BMP part #1
-        U+10000..U+10FFFF -> [01][00][00]..[10][FF][FF] Supplementary
-        U+E000..U+FFFF    -> [20][E0][00]..[20][FF][FF] BMP part #2
-      */
-      if (wc >= 0xE000 && wc <= 0xFFFF)
-        wc+= 0x200000;
-    }
     *dst++= (uchar) (wc >> 16);
     *dst++= (uchar) ((wc >> 8) & 0xFF);
     *dst++= (uchar) (wc & 0xFF);