[TSan][Darwin] Fix shadow mapping for iOS simulator on Apple Silicon

With the introduction of Apple Silicon `defined(__aarch64__)` is not a
reliable way to check for the platform anymore.

We want to use the "normal" `Mapping48AddressSpace` mapping everywhere
except devices, including the iOS simulators on AS.

Relevant revisions:
https://reviews.llvm.org/D35147
https://reviews.llvm.org/D86377
https://reviews.llvm.org/D107743
https://reviews.llvm.org/D107888

Differential Revision: https://reviews.llvm.org/D115843

compiler-rt/lib/tsan/rtl/tsan_platform.h

@@ -585,11 +585,11 @@ ALWAYS_INLINE auto SelectMapping(Arg arg) {
   return Func::template Apply<MappingGo48>(arg);
 #  endif
 #else  // SANITIZER_GO
-#  if defined(__x86_64__) || SANITIZER_IOSSIM || SANITIZER_MAC && !SANITIZER_IOS
-  return Func::template Apply<Mapping48AddressSpace>(arg);
-#  elif defined(__aarch64__) && defined(__APPLE__)
+#  if SANITIZER_IOS && !SANITIZER_IOSSIM
   return Func::template Apply<MappingAppleAarch64>(arg);
-#  elif defined(__aarch64__) && !defined(__APPLE__)
+#  elif defined(__x86_64__) || SANITIZER_MAC
+  return Func::template Apply<Mapping48AddressSpace>(arg);
+#  elif defined(__aarch64__)
   switch (vmaSize) {
     case 39:
       return Func::template Apply<MappingAarch64_39>(arg);

compiler-rt/lib/tsan/rtl/tsan_platform_posix.cpp

@@ -110,7 +110,7 @@ void CheckAndProtect() {
     Die();
   }
 
-#    if defined(__aarch64__) && defined(__APPLE__) && SANITIZER_IOS
+#    if SANITIZER_IOS && !SANITIZER_IOSSIM
   ProtectRange(HeapMemEnd(), ShadowBeg());
   ProtectRange(ShadowEnd(), MetaShadowBeg());
   ProtectRange(MetaShadowEnd(), HiAppMemBeg());