Add patch to explicitly link _ctypes module with -ldl (#1537489)

Add patch to explicitly link _ctypes module with -ldl (#1537489)
Refactored patch for libxcrypt
Re-enable strict symbol checks in the link editor

python37.spec

@@ -167,11 +167,6 @@ License: Python
 # on files that test invalid syntax.
 %undefine py_auto_byte_compile
 
-# Disable strict symbol checks in the link editor.
-# See: https://src.fedoraproject.org/rpms/redhat-rpm-config/c/078af192613e1beec34824a94dc5f6feeeea1568?branch=master
-# https://bugzilla.redhat.com/show_bug.cgi?id=1537489
-%undefine _strict_symbol_defs_build
-
 # For multilib support, files that are different between 32- and 64-bit arches
 # need different filenames. Use "64" or "32" according to the word size.
 # Currently, the best way to determine an architecture's word size happens to
@@ -386,6 +381,12 @@ Patch289: 00289-fix-nis-compilation.patch
 # Reported upstream: https://bugs.python.org/issue32635
 Patch290: 00290-cryptmodule-Include-crypt.h-for-declaration-of-crypt.patch
 
+# 00291 #
+# Build fails with undefined references to dlopen / dlsym otherwise.
+# See: https://bugzilla.redhat.com/show_bug.cgi?id=1537489
+# and: https://src.fedoraproject.org/rpms/redhat-rpm-config/c/078af19
+Patch291: 00291-setup-Link-ctypes-against-dl-explicitly.patch
+
 # (New patches go here ^^^)
 #
 # When adding new patches to "python" and "python3" in Fedora, EL, etc.,
@@ -689,6 +690,7 @@ sed -r -i s/'_PIP_VERSION = "[0-9.]+"'/'_PIP_VERSION = "%{pip_version}"'/ Lib/en
 %patch274 -p1
 %patch289 -p1
 %patch290 -p1
+%patch291 -p1
 
 
 # Remove files that should be generated by the build