bumping Swift version from 4.2 to 4.2.1 rdar://problem/43124673

Author: najacque

CMakeLists.txt

@@ -128,7 +128,7 @@ set_property(CACHE SWIFT_ANALYZE_CODE_COVERAGE PROPERTY
 # SWIFT_VERSION is deliberately /not/ cached so that an existing build directory
 # can be reused when a new version of Swift comes out (assuming the user hasn't
 # manually set it as part of their own CMake configuration).
-set(SWIFT_VERSION "4.2")
+set(SWIFT_VERSION "4.2.1")
 
 set(SWIFT_VENDOR "" CACHE STRING
     "The vendor name of the Swift compiler")

test/Serialization/Recovery/crash-recovery.swift

@@ -14,7 +14,7 @@ public class Sub: Base {
 
 // CHECK-CRASH: error: fatal error encountered while reading from module 'Lib'; please file a bug report with your project and the crash log
 // CHECK-CRASH-3-NOT: note
-// CHECK-CRASH-4: note: compiling as Swift 4.2, with 'Lib' built as Swift 3.4
+// CHECK-CRASH-4: note: compiling as Swift 4.2.1, with 'Lib' built as Swift 3.4
 // CHECK-CRASH-LABEL: *** DESERIALIZATION FAILURE (please include this section in any bug report) ***
 // CHECK-CRASH: could not find 'disappearingMethod()' in parent class
 // CHECK-CRASH: While loading members for 'Sub' in module 'Lib'

test/Serialization/Recovery/types-4-to-3.swift

@@ -16,8 +16,8 @@ import Lib
 func requiresConformance(_: B_RequiresConformance<B_ConformsToProto>) {}
 func requiresConformance(_: B_RequiresConformance<C_RelyOnConformanceImpl.Assoc>) {}
 
-class Sub: Base {} // expected-error {{cannot inherit from class 'Base' (compiled with Swift 4.1.50) because it has overridable members that could not be loaded in Swift 3.4}}
-class Impl: Proto {} // expected-error {{type 'Impl' cannot conform to protocol 'Proto' (compiled with Swift 4.1.50) because it has requirements that could not be loaded in Swift 3.4}}
+class Sub: Base {} // expected-error {{cannot inherit from class 'Base' (compiled with Swift 4.2.1) because it has overridable members that could not be loaded in Swift 3.4}}
+class Impl: Proto {} // expected-error {{type 'Impl' cannot conform to protocol 'Proto' (compiled with Swift 4.2.1) because it has requirements that could not be loaded in Swift 3.4}}
 
 #else // TEST