[Test] Use %target-cpu to generalize test for all architectures

Author: DougGregor

test/attr/typed_throws_availability_osx.swift

@@ -1,15 +1,15 @@
-// RUN: %swift -typecheck -verify -target x86_64-apple-macosx10.10 %s -enable-experimental-feature TypedThrows
+// RUN: %swift -typecheck -verify -target %target-cpu-apple-macosx11 %s -enable-experimental-feature TypedThrows
 
 // REQUIRES: OS=macosx
 
-@available(macOS 12, *)
+@available(macOS 13, *)
 enum MyError: Error {
   case fail
 }
 
-@available(macOS 11, *)
+@available(macOS 12, *)
 func throwMyErrorBadly() throws(MyError) { }
-// expected-error@-1{{'MyError' is only available in macOS 12 or newer}}
+// expected-error@-1{{'MyError' is only available in macOS 13 or newer}}