MdeModulePkg RegularExpressionDxe: Update Oniguruma from v6.9.0 to v6.9.3

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2066
Update Oniguruma to the latest version v6.9.3.
Oniguruma https://github.com/kkos/oniguruma
This release is the security fix release. It includes the changes:
Fixed CVE-2019-13224
Fixed CVE-2019-13225
Fixed many problems (found by libfuzzer programs)

Verify VS2015, GCC5 build.
Verify RegularExpressionProtocol GetInfo() and Match() function.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Cinnamon Shia <cinnamon.shia@hpe.com>
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>

MdeModulePkg/Universal/RegularExpressionDxe/Oniguruma/regposerr.c

@@ -2,7 +2,7 @@
   regposerr.c - Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -37,13 +37,7 @@
 //#include "config.h"
 #include "onigposix.h"
 
-#if 0
-#ifdef HAVE_STRING_H
-# include <string.h>
-#else
-# include <strings.h>
-#endif
-#endif
+//#include <string.h>
 
 #if defined(__GNUC__)
 #  define ARG_UNUSED  __attribute__ ((unused))
@@ -86,7 +80,7 @@ static char* ESTRING[] = {
 
 extern size_t
 regerror(int posix_ecode, const regex_t* reg ARG_UNUSED, char* buf,
-	 size_t size)
+         size_t size)
 {
   char* s;
   char tbuf[35];