package/libebml: fix build with gcc 11

Fix the following build failure with gcc 11:

/tmp/instance-0/output-1/build/libebml-1.4.2/src/EbmlString.cpp: In member function 'virtual filepos_t libebml::EbmlString::ReadData(libebml::IOCallback&, libebml::ScopeMode)':
/tmp/instance-0/output-1/build/libebml-1.4.2/src/EbmlString.cpp:147:41: error: 'numeric_limits' is not a member of 'std'
  147 |     auto Buffer = (GetSize() + 1 < std::numeric_limits<std::size_t>::max()) ? new (std::nothrow) char[GetSize() + 1] : nullptr;
      |                                         ^~~~~~~~~~~~~~
/tmp/instance-0/output-1/build/libebml-1.4.2/src/EbmlString.cpp:147:67: error: expected primary-expression before '>' token
  147 |     auto Buffer = (GetSize() + 1 < std::numeric_limits<std::size_t>::max()) ? new (std::nothrow) char[GetSize() + 1] : nullptr;
      |                                                                   ^
/tmp/instance-0/output-1/build/libebml-1.4.2/src/EbmlString.cpp:147:70: error: '::max' has not been declared; did you mean 'std::max'?
  147 |     auto Buffer = (GetSize() + 1 < std::numeric_limits<std::size_t>::max()) ? new (std::nothrow) char[GetSize() + 1] : nullptr;
      |                                                                      ^~~
      |                                                                      std::max

Fixes:
 - http://autobuild.buildroot.org/results/3a28507127eae47994ca62e2b656da32bd2fb1f8

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/libebml/0001-include-appropriate-header-files-for-std-numeric_limits.patch

@@ -0,0 +1,52 @@
+From f0bfd53647961e799a43d918c46cf3b6bff89806 Mon Sep 17 00:00:00 2001
+From: Moritz Bunkus <mo@bunkus.online>
+Date: Sat, 27 Feb 2021 20:36:52 +0100
+Subject: [PATCH] include appropriate header files for std::numeric_limits
+
+Fixes #80.
+
+[Retrieved from:
+https://github.com/Matroska-Org/libebml/commit/f0bfd53647961e799a43d918c46cf3b6bff89806]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ ChangeLog                 | 4 ++++
+ src/EbmlString.cpp        | 1 +
+ src/EbmlUnicodeString.cpp | 1 +
+ 3 files changed, 6 insertions(+)
+
+diff --git a/ChangeLog b/ChangeLog
+index 034cf86..e4b13a9 100644
+--- a/ChangeLog
++++ b/ChangeLog
+@@ -1,3 +1,7 @@
++2021-02-27  Moritz Bunkus  <mo@bunkus.online>
++
++        * Fix compilation with g++ 11. Fixes #80.
++
+ 2021-02-21 Steve Lhomme <slhomme@matroska.org>
+ 
+         * Remove Coremake project files
+diff --git a/src/EbmlString.cpp b/src/EbmlString.cpp
+index 27e55fd..4c05fcf 100644
+--- a/src/EbmlString.cpp
++++ b/src/EbmlString.cpp
+@@ -34,6 +34,7 @@
+   \author Steve Lhomme     <robux4 @ users.sf.net>
+ */
+ #include <cassert>
++#include <limits>
+ 
+ #include "ebml/EbmlString.h"
+ 
+diff --git a/src/EbmlUnicodeString.cpp b/src/EbmlUnicodeString.cpp
+index 496a16a..99fc073 100644
+--- a/src/EbmlUnicodeString.cpp
++++ b/src/EbmlUnicodeString.cpp
+@@ -36,6 +36,7 @@
+ */
+ 
+ #include <cassert>
++#include <limits>
+ 
+ #include "ebml/EbmlUnicodeString.h"
+