[vm] Fix simarm_x64 build on mac

Bug: #36839
Change-Id: I0586ae3262c832519a36c409433db35e196b2019
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/108203
Commit-Queue: Liam Appelbe <[email protected]>
Auto-Submit: Liam Appelbe <[email protected]>
Reviewed-by: Siva Annamalai <[email protected]>

Author: liamappelbe

runtime/vm/compiler/assembler/assembler_arm.cc

@@ -15,8 +15,8 @@
 
 // An extra check since we are assuming the existence of /proc/cpuinfo below.
 #if !defined(USING_SIMULATOR) && !defined(__linux__) && !defined(ANDROID) &&   \
-    !HOST_OS_IOS
-#error ARM cross-compile only supported on Linux
+    !defined(HOST_OS_IOS) && !defined(HOST_OS_MACOS)
+#error ARM cross-compile only supported on Linux, Android, iOS, and Mac
 #endif
 
 namespace dart {