Introduce armv9-a arch variant.

Armv9 with mandatory PAC and BTI extensions.
Stack protector is disabled as it is irrelevant with PAC.

Bug: 263283855
Test: NFC
Change-Id: I2f298f21dade12824597e0a6920772a2bfc63afb
diff --git a/android/arch_list.go b/android/arch_list.go
index 578904c..07777c1 100644
--- a/android/arch_list.go
+++ b/android/arch_list.go
@@ -26,6 +26,7 @@
 		"armv8-a-branchprot",
 		"armv8-2a",
 		"armv8-2a-dotprod",
+		"armv9-a",
 	},
 	X86: {
 		"amberlake",
@@ -148,6 +149,9 @@
 		"armv8-2a-dotprod": {
 			"dotprod",
 		},
+		"armv9-a": {
+			"dotprod",
+		},
 	},
 	X86: {
 		"amberlake": {