Merge pull request #85898 from rjmansfield/fix-issue-78598-back-deployment

[test] Mark issue-78598.swift as unsupported on back deployment runtime.

Author: rjmansfield

test/Interpreter/issue-78598.swift

@@ -1,9 +1,12 @@
-// RUN: %target-run-simple-swift(-target %target-swift-5.9-abi-triple %no-fixup-chains) | %FileCheck %s
+// RUN: %target-run-simple-swift(-target %target-swift-5.9-abi-triple) | %FileCheck %s
 
 // https://github.com/swiftlang/swift/issues/78598
 
 // REQUIRES: executable_test
 
+// This test needs a Swift 5.9 runtime or newer.
+// UNSUPPORTED: back_deployment_runtime
+
 var counter = 0
 
 final class Entry<Results> {