[llvm] [llvm][docs] MemTagSanitizer is only supported on AArch64 Android (PR #120545)

[Fangrui Song via llvm-commits]

================
@@ -28,10 +28,15 @@ memory bugs.
 Usage
 =====
 
-Compile and link your program with ``-fsanitize=memtag`` flag. This
-will only work when targeting AArch64 with MemTag extension. One
-possible way to achieve that is to add ``-target
-aarch64-linux -march=armv8+memtag`` to compilation flags.
+Compile and link your program with the ``-fsanitize=memtag`` flag. This
+will only work when targeting AArch64 Android with the memory tagging extension.
+One possible way to achieve that is to add ``-target
----------------
MaskRay wrote:

Use `--target=` instead of the deprecated `-target`

https://github.com/llvm/llvm-project/pull/120545