Merge pull request #24994 from jckarter/SR-10264-test

Add regression test for SR-10264

Author: jckarter

test/Interpreter/Inputs/testable_key_path_2.swift

@@ -0,0 +1,3 @@
+internal class TestClass {
+  internal var field = "goodbye"
+}

test/Interpreter/testable_key_path.swift

@@ -0,0 +1,20 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift -force-single-frontend-invocation -c -o %t/Module.o -enable-testing -parse-as-library -emit-module -emit-module-path %t/Module.swiftmodule -module-name Module %S/Inputs/testable_key_path_2.swift
+// RUN: %target-build-swift -o %t/a.out -I %t %s %t/Module.o
+// RUN: %target-run %t/a.out | %FileCheck %s
+
+// REQUIRES: executable_test
+
+@testable import Module
+
+let c = TestClass()
+
+print("You say \(c.field)")
+
+let kp = \TestClass.field
+
+c[keyPath: kp] = "hello"
+
+print("I say \(c.field)")
+
+// CHECK: I say hello