Fix missing patch

Related: rhbz#1975234

cmake-3.20.4-glibc_libdl.patch

@@ -0,0 +1,62 @@
+From 635ab930f6185d1ec3e4d99109e2edf0533b0d00 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Bj=C3=B6rn=20Esser?= <besser82@fedoraproject.org>
+Date: Wed, 23 Jun 2021 21:03:15 +0200
+Subject: [PATCH] testDynamicLoader: Use LIBDL_SO macro if defined.
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Starting with glibc v2.34 there is no external version of libdl.so
+anymore.  It has been merged into the glibc libc.so.
+
+Assuming libdl.so will be present will break the test, thus the
+LIBDL_SO macro should be used.  If the macro is not defined on
+the system, we ensure it will be defined using the previously
+hardcoded value.
+
+Signed-off-by: Björn Esser <besser82@fedoraproject.org>
+---
+ cmake-3.20.4/Source/kwsys/testDynamicLoader.cxx | 14 ++++++++++++--
+ 1 file changed, 12 insertions(+), 2 deletions(-)
+
+Index: cmake-3.21.0-rc1/Source/kwsys/testDynamicLoader.cxx
+===================================================================
+--- cmake-3.21.0-rc1.orig/Source/kwsys/testDynamicLoader.cxx
++++ cmake-3.21.0-rc1/Source/kwsys/testDynamicLoader.cxx
+@@ -8,6 +8,25 @@
+ #  include <be/kernel/OS.h> /* disable_debugger() API. */
+ #endif
+ 
++// Needed for __GLIBC__ test macro.
++#ifdef __linux__
++#  include <features.h>
++#endif
++
++// Will define LIBDL_SO macro on systems with glibc.
++#ifdef __GLIBC__
++#  include <gnu/lib-names.h>
++// Define to LIBC_SO, if not defined by above header.
++#  ifndef LIBDL_SO
++#    define LIBDL_SO LIBC_SO
++#  endif
++#endif
++
++// Define the LIBDL_SO macro, if not defined above.
++#ifndef LIBDL_SO
++#  define LIBDL_SO "libdl.so"
++#endif
++
+ // Work-around CMake dependency scanning limitation.  This must
+ // duplicate the above list of headers.
+ #if 0
+@@ -107,8 +126,8 @@ int testDynamicLoader(int argc, char* ar
+   // This one is actually fun to test, since dlopen is by default
+   // loaded...wonder why :)
+   res += TestDynamicLoader("foobar.lib", "dlopen", 0, 1, 0);
+-  res += TestDynamicLoader("libdl.so", "dlopen", 1, 1, 1);
+-  res += TestDynamicLoader("libdl.so", "TestDynamicLoader", 1, 0, 1);
++  res += TestDynamicLoader(LIBDL_SO, "dlopen", 1, 1, 1);
++  res += TestDynamicLoader(LIBDL_SO, "TestDynamicLoader", 1, 0, 1);
+ #endif
+   // Now try on the generated library
+   std::string libname = GetLibName(KWSYS_NAMESPACE_STRING "TestDynload");