MDEV-22003 mysql_config disappeared from 10.5 (e.g. binary tarball or source build)

* generate and install mysql_config
* symlink mariadb_config (from C/C) to mariadb-config

also:
* .gitignore generated mariadb-config.1
* remove obsolete compiler flag from C/C

.gitignore

@@ -579,6 +579,7 @@ man/mariadb-binlog.1
 man/mariadb-check.1
 man/mariadb-client-test-embedded.1
 man/mariadb-client-test.1
+man/mariadb-config.1
 man/mariadb-convert-table-format.1
 man/mariadb-dump.1
 man/mariadb-dumpslow.1

cmake/mariadb_connector_c.cmake

@@ -38,7 +38,10 @@ SET(CLIENT_PLUGIN_PVIO_SOCKET STATIC)
 MESSAGE("== Configuring MariaDB Connector/C")
 ADD_SUBDIRECTORY(libmariadb)
 
-#remove after merging libmariadb > v3.0.9
-IF(TARGET caching_sha2_password AND CMAKE_C_FLAGS_DEBUG MATCHES "-Werror")
-  SET_PROPERTY(TARGET caching_sha2_password APPEND_STRING PROPERTY COMPILE_FLAGS -Wno-unused-function)
+IF(UNIX)
+  INSTALL(CODE "EXECUTE_PROCESS(
+                  COMMAND ${CMAKE_COMMAND} -E make_directory ${INSTALL_BINDIR}
+                  COMMAND ${CMAKE_COMMAND} -E create_symlink mariadb_config ${INSTALL_BINDIR}/mariadb-config
+                  WORKING_DIRECTORY \$ENV{DESTDIR}\${CMAKE_INSTALL_PREFIX})"
+          COMPONENT Development)
 ENDIF()

debian/libmariadb-dev-compat.install

@@ -2,3 +2,4 @@ usr/lib/*/libmysqlclient.a
 usr/lib/*/libmysqlclient.so
 usr/lib/*/libmysqlclient_r.a
 usr/lib/*/libmysqlclient_r.so
+usr/bin/mysql_config

debian/libmariadb-dev-compat.links

 #!/usr/bin/dh-exec
-usr/bin/mariadb_config usr/bin/mysql_config
 usr/include/mariadb usr/include/mysql
 usr/lib/${DEB_HOST_MULTIARCH}/pkgconfig/mariadb.pc usr/lib/${DEB_HOST_MULTIARCH}/pkgconfig/mysqlclient.pc

scripts/CMakeLists.txt

@@ -313,6 +313,7 @@ ELSE()
     mariadb-access
     mariadb-convert-table-format
     mariadb-find-rows
+    mysql_config
     mytop
     mariadb-hotcopy
     ${SERVER_SCRIPTS}