Extract some common definitions.

cmake/config.cmake

@@ -0,0 +1,26 @@
+if (NOT NO_ISA_EXTENSIONS)
+    include(CheckCXXCompilerFlag)
+    if (CMAKE_SYSTEM_PROCESSOR MATCHES "aarch64" OR CMAKE_SYSTEM_PROCESSOR MATCHES "arm64")
+        CHECK_CXX_COMPILER_FLAG("-mcpu=native" COMPILER_SUPPORTS_MCPU_NATIVE)
+        if(COMPILER_SUPPORTS_MARCH_NATIVE)
+            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mcpu=native")
+            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mcpu=native")
+        endif()
+    else()
+        CHECK_CXX_COMPILER_FLAG("-march=native" COMPILER_SUPPORTS_MARCH_NATIVE)
+        if(COMPILER_SUPPORTS_MARCH_NATIVE)
+            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native")
+            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=native")
+        endif()
+    endif()
+endif()
+
+if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND NOT LEGACY)
+    set(USE_WAYLAND ON)
+else()
+    set(USE_WAYLAND OFF)
+endif()
+
+if(WIN32)
+    add_definitions(-DNOMINMAX -DWIN32_LEAN_AND_MEAN)
+endif()