[mac-arm64] Fix missing #include

For an "#if defined(MAP_JIT)" test to work as expected, <sys/mman.h>
must be included in the compilation unit.

Bug: chromium:1144200
Change-Id: Ia0bf35ec1872c02457f1fbc0ee6689c7f7d27d4a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2517689
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70986}

src/base/page-allocator.cc

@@ -6,6 +6,10 @@
 
 #include "src/base/platform/platform.h"
 
+#if V8_OS_MACOSX
+#include <sys/mman.h>  // For MAP_JIT.
+#endif
+
 namespace v8 {
 namespace base {