LibCore: Remove workarounds for system header global name conflicts

Userland/Libraries/LibCore/IOSurface.cpp

@@ -11,11 +11,7 @@
 static_assert(false, "This file must only be used for macOS");
 #endif
 
-#define FixedPoint FixedPointMacOS
-#define Duration DurationMacOS
-#include <IOSurface/IOSurface.h>
-#undef FixedPoint
-#undef Duration
+#import <IOSurface/IOSurface.h>
 
 namespace Core {
 

Userland/Libraries/LibCore/MetalContext.mm

@@ -7,11 +7,7 @@
 #include <AK/OwnPtr.h>
 #include <LibCore/MetalContext.h>
 
-#define FixedPoint FixedPointMacOS
-#define Duration DurationMacOS
-#include <Metal/Metal.h>
-#undef FixedPoint
-#undef Duration
+#import <Metal/Metal.h>
 
 namespace Core {