Mark a recent compiler crasher as non-deterministic

Author: CodaFi

validation-test/compiler_crashers/28543-unreachable-executed-at-swift-include-swift-ast-typevisitor-h-39.swift

@@ -5,5 +5,7 @@
 // See https://swift.org/LICENSE.txt for license information
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
+// REQUIRES: deterministic-behavior
+// Type checking causes a use-after-free.
 // RUN: not --crash %target-swift-frontend %s -emit-ir
 ([-.f\n{}{$0(n&[]{