[mac-arm] Fix typo in preprocessor check

Change-Id: Ic1130d1bba3f70906cd39685bfa45b214424c2e3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2644952
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72271}

src/base/cpu.cc

@@ -740,7 +740,7 @@ CPU::CPU()
     has_jscvt_ = HasListItem(features, "jscvt");
     delete[] features;
   }
-#elif V8_OS_MAC
+#elif V8_OS_MACOSX
   // ARM64 Macs always have JSCVT.
   has_jscvt_ = true;
 #endif  // V8_OS_WIN