Update the SwiftStdlib version to 6.0 and fix Frontend/crash.swift test

Author: shahmishal

test/Distributed/Macros/distributed_macro_expansion_DistributedProtocol_inheritance.swift

@@ -46,14 +46,14 @@ protocol G3<ActorSystem>: DistributedActor, EmptyBase where ActorSystem: Distrib
 
 // CHECK: extension G3 where Self: Distributed._DistributedActorStub {
 // CHECK:   func get() -> String {
-// CHECK:     if #available (SwiftStdlib 5.11, *) {
+// CHECK:     if #available (SwiftStdlib 6.0, *) {
 // CHECK:       Distributed._distributedStubFatalError()
 // CHECK:     } else {
 // CHECK:       fatalError()
 // CHECK:     }
 // CHECK:   }
 // CHECK:   distributed func greet(name: String) -> String {
-// CHECK:     if #available (SwiftStdlib 5.11, *) {
+// CHECK:     if #available (SwiftStdlib 6.0, *) {
 // CHECK:       Distributed._distributedStubFatalError()
 // CHECK:     } else {
 // CHECK:       fatalError()

test/Frontend/crash.swift

@@ -18,7 +18,7 @@
 
 // RUN: not --crash %target-swift-frontend -typecheck -debug-crash-after-parse -experimental-allow-module-with-compiler-errors -swift-version 5 %s 2>&1 | %FileCheck -check-prefix CHECK-CURRENT %s
 // CHECK-CURRENT: Program arguments: {{.*}} -experimental-allow-module-with-compiler-errors
-// CHECK-CURRENT: Compiling with the current language version while allowing modules with compiler errors
+// CHECK-CURRENT: Compiling with effective version {{.*}} while allowing modules with compiler errors
 
 func anchor() {}
 anchor()

test/Runtime/demangleToMetadataTransferring.swift

@@ -21,7 +21,7 @@ class Klass {}
 
 let DemangleToMetadataTests = TestSuite("DemangleToMetadata")
 
-if #available(SwiftStdlib 5.11, *) {
+if #available(SwiftStdlib 6.0, *) {
   DemangleToMetadataTests.test("transferring parameter") {
     typealias Fn = (transferring Klass) -> Void
     expectEqual("y4main5KlassCnYuc", _mangledTypeName(Fn.self)!)