Fix LTO (aka interprocedural optimization) build with MSVC

Also, disable MSVC LTO for static client libraries - they won't be usable for end-users.

Author: vaintroub

cmake/libutils.cmake

@@ -370,5 +370,11 @@ ENDFUNCTION()
 FUNCTION (MAYBE_DISABLE_IPO target)
  IF(MSVC AND NOT CLANG_CL)
  SET_TARGET_PROPERTIES(${target} PROPERTIES INTERPROCEDURAL_OPTIMIZATION OFF)
+ IF(CMAKE_CONFIGURATION_TYPES)
+ FOREACH(cfg ${CMAKE_CONFIGURATION_TYPES})
+ STRING(TOUPPER "${cfg}" cfg_upper)
+ SET_TARGET_PROPERTIES(${target} PROPERTIES INTERPROCEDURAL_OPTIMIZATION_${cfg_upper} OFF)
+ ENDFOREACH()
+ ENDIF()
  ENDIF()
 ENDFUNCTION()

cmake/mariadb_connector_c.cmake

@@ -40,6 +40,13 @@ SET(CLIENT_PLUGIN_PVIO_SOCKET STATIC)
 MESSAGE("== Configuring MariaDB Connector/C")
 ADD_SUBDIRECTORY(libmariadb)
 
+IF(MSVC AND TARGET mariadb_obj AND TARGET mariadbclient)
+ # With MSVC, do not produce LTCG-compiled static client libraries.
+ # They are not usable by end-users, being tied to exact compiler version
+ MAYBE_DISABLE_IPO(mariadb_obj)
+ MAYBE_DISABLE_IPO(mariadbclient)
+ENDIF()
+
 IF(UNIX)
  INSTALL(CODE "EXECUTE_PROCESS(
  COMMAND ${CMAKE_COMMAND} -E make_directory \$ENV{DESTDIR}\${CMAKE_INSTALL_PREFIX}/${INSTALL_BINDIR})