Add missing include for errno.h

Author: janisozaur

Source/Main.cpp

@@ -20,6 +20,8 @@
 
 #include "windows_h_filters.h"
 
+#include <errno.h>
+
 #include "allegro.h"
 #include "SDL.h"
 

external/sources/allegro 4.4.3.1-custom/include/allegro/inline/fmaths.inl

@@ -23,6 +23,8 @@
 #include "asm.inl"
 #undef ALLEGRO_IMPORT_MATH_ASM
 
+#include <errno.h>
+
 #ifdef __cplusplus
    extern "C" {
 #endif