[LTO FTBFS] Responsible upstream code found, switch back to building with LTO

reverting the upstream change for now

lto-type-mismatch.patch

@@ -0,0 +1,40 @@
+This code has been introduced by Upstream in the commit:
+  https://github.com/mariadb-corporation/mariadb-connector-c/commit/1acb81e
+and later modified in the:
+  https://github.com/mariadb-corporation/mariadb-connector-c/commit/5f88f50
+between the version mariadb-connector-c 3.3.5 and 3.3.7
+
+It results in a lot of warnings being treated as errors and thus killing the compilation.
+Specifically lot of occuerences of these:
+| libmariadb/ma_client_plugin.c:83:39: error: type of ‘mysql_native_password_client_plugin’ does not match original declaration [-Werror=lto-type-mismatch]
+| libmariadb/ma_client_plugin.c:84:39: error: type of ‘mysql_old_password_client_plugin’ does not match original declaration [-Werror=lto-type-mismatch]
+| libmariadb/ma_client_plugin.c:85:39: error: type of ‘zlib_client_plugin’ does not match original declaration [-Werror=lto-type-mismatch]
+| libmariadb/ma_client_plugin.c:86:39: error: type of ‘pvio_socket_client_plugin’ does not match original declaration [-Werror=lto-type-mismatch]
+
+Note: These warnings were present even before:
+e.g. this build.log of release 3.3.5:
+  https://koji.fedoraproject.org/koji/buildinfo?buildID=2244099
+  https://kojipkgs.fedoraproject.org//packages/mariadb-connector-c/3.3.5/2.fc39/data/logs/x86_64/build.log
+  search for "[-Wlto-type-mismatch]"
+
+The difference is that since they started to be treated as errors and thus killing the build.
+
+--- mariadb-connector-c-3.3.8-src/CMakeLists.txt	2023-11-01 11:28:04.000000000 +0100
++++ mariadb-connector-c-3.3.8-src/CMakeLists.txt_patched	2024-01-12 20:57:58.031375024 +0100
+@@ -395,16 +395,6 @@ ENDIF()
+ MESSAGE1(SYSTEM_LIBS "SYSTEM_LIBS ${SYSTEM_LIBS}")
+ MARK_AS_ADVANCED(SYSTEM_LIBS)
+ 
+-IF(NOT IS_SUBPROJECT)
+-IF ((NOT WIN32) AND (CMAKE_C_COMPILER_ID MATCHES "Clang" OR CMAKE_C_COMPILER_ID MATCHES "GNU"))
+-  SET(WARNING_AS_ERROR "-Werror")
+-ELSEIF(CMAKE_C_COMPILER_ID MATCHES "MSVC")
+-  SET(WARNING_AS_ERROR "/WX")
+-ENDIF()
+-SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${WARNING_AS_ERROR}")
+-ENDIF()
+-
+-
+ IF(NOT REMOTEIO_PLUGIN_TYPE MATCHES "OFF")
+   IF(CURL_FOUND)
+     INCLUDE_DIRECTORIES(${CURL_INCLUDE_DIRS})

mariadb-connector-c.spec

@@ -3,10 +3,6 @@
 # Enable building and packing of the testsuite
 %bcond_without  testsuite
 
-# TEMPORARY WORKAROUND:
-#   Build fails since 3.3.6 with LTO flags enabled
-#   Reported as rhbz#2257198
-%global _lto_cflags %{nil}
 
 
 Name:           mariadb-connector-c
@@ -24,6 +20,8 @@ Url:            http://mariadb.org/
 Patch1:         testsuite.patch
 %endif
 
+Patch2:         lto-type-mismatch.patch
+
 Requires:       %{_sysconfdir}/my.cnf
 BuildRequires:  gcc-c++ cmake openssl-devel zlib-devel libzstd-devel
 # Remote-IO plugin
@@ -92,6 +90,7 @@ and require this package, so the /etc/my.cnf file is present.
 %if %{with testsuite}
 %patch -P1 -p1
 %endif
+%patch -P2 -p1
 
 # Remove unsused parts
 rm -r win win-iconv external/zlib