Add a mode to test implicit dynamic with private imports

Author: aschwaighofer

Darwin/Foundation-swiftoverlay-Tests/TestData.swift

@@ -17,6 +17,9 @@
 // REQUIRES: executable_test
 // REQUIRES: objc_interop
 
+// Requires swift-version 4
+// UNSUPPORTED: swift_test_mode_optimize_none_with_implicit_dynamic
+
 import Foundation
 import Dispatch
 import ObjectiveC

Darwin/Foundation-swiftoverlay-Tests/TestIndexSet.swift

@@ -10,6 +10,9 @@
 // REQUIRES: executable_test
 // REQUIRES: objc_interop
 
+// Requires swift-version 4
+// UNSUPPORTED: swift_test_mode_optimize_none_with_implicit_dynamic
+
 import Foundation
 
 #if FOUNDATION_XCTEST

Darwin/Foundation-swiftoverlay-Tests/TestMeasurement.swift

@@ -10,6 +10,9 @@
 // REQUIRES: executable_test
 // REQUIRES: objc_interop
 
+// Requires swift-version 4
+// UNSUPPORTED: swift_test_mode_optimize_none_with_implicit_dynamic
+
 import Foundation
 
 #if FOUNDATION_XCTEST