⬆️ Bump CMake to 3.13

This allows us to have variables set in the toolchains which cleans up
the main file a bit.

CMake/mingwcc.cmake

@@ -17,3 +17,6 @@ SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 
 SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.3)
+  SET(DISABLE_LTO ON)
+endif()

CMake/mingwcc64.cmake

@@ -18,3 +18,4 @@ SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 SET(SYSTEM_BITS x64)
+SET(DISABLE_LTO ON)

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.10) # CMP0083 NEW
+cmake_minimum_required(VERSION 3.13) # CMP0083 NEW
 
 include(CMake/out_of_tree.cmake)
 include(CMake/genex.cmake)
@@ -58,12 +58,6 @@ else()
     LANGUAGES C CXX)
 endif()
 
-if(WIN32 AND NOT CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
-  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.3 OR SYSTEM_BITS MATCHES x64)
-    SET(DISABLE_LTO ON)
-  endif()
-endif()
-
 # Not a genexp because CMake doesn't support it
 # https://gitlab.kitware.com/cmake/cmake/-/issues/20546
 if(NOT DISABLE_LTO)