Add support for ARMv9.3-A and ARMv9.4-A.

Bug: 364383722
Test: presubmit, internal build with the new arch variant
Change-Id: I151d7f5953cbec10e64887184a04d9121cde63e9
diff --git a/rust/config/arm64_device.go b/rust/config/arm64_device.go
index 94a4457..efcd56a 100644
--- a/rust/config/arm64_device.go
+++ b/rust/config/arm64_device.go
@@ -45,6 +45,14 @@
 			"-Z branch-protection=bti,pac-ret",
 			"-Z stack-protector=none",
 		},
+		"armv9-3a": []string{
+			"-Z branch-protection=bti,pac-ret",
+			"-Z stack-protector=none",
+		},
+		"armv9-4a": []string{
+			"-Z branch-protection=bti,pac-ret",
+			"-Z stack-protector=none",
+		},
 	}
 )