[IRGen][Test] Use the new availability support.

We need to only generate references to `_swift_exceptionPersonality`
if we're building for a new enough runtime.  The previous code was
good on Darwin, but would have resulted in build problems on Linux.

rdar://120952971

Author: al45tair

include/swift/AST/FeatureAvailability.def

@@ -59,6 +59,7 @@ FEATURE(SignedDescriptor,                               (5, 9))
 FEATURE(ObjCSymbolicReferences,                         (5, 11))
 FEATURE(TypedThrows,                                    (5, 11))
 FEATURE(StaticReadOnlyArrays,                           (5, 11))
+FEATURE(SwiftExceptionPersonality,                      (5, 11))
 
 FEATURE(TaskExecutor,                                   FUTURE)
 FEATURE(Differentiation,                                FUTURE)

lib/IRGen/GenCall.cpp

@@ -4997,11 +4997,9 @@ void IRGenFunction::emitEpilogue() {
 
     auto deploymentAvailability =
       AvailabilityContext::forDeploymentTarget(IGM.Context);
-    bool canUseSwiftPersonality = deploymentAvailability.isContainedIn(
-      IGM.Context.getSwift511Availability());
     llvm::Constant *personality;
 
-    if (canUseSwiftPersonality) {
+    if (IGM.isSwiftExceptionPersonalityFeatureAvailable()) {
       // The function should use our personality routine
       auto swiftPersonality = IGM.getExceptionPersonalityFunctionPointer();
       personality = swiftPersonality.getDirectPointer();

test/Interop/Cxx/exceptions/objc-trap-on-exception-irgen-itanium.swift

@@ -1,7 +1,8 @@
 // RUN: %empty-directory(%t)
 // RUN: split-file %s %t
 
-// RUN: %target-swift-emit-ir %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop | %FileCheck %s
+// RUN: %target-swift-emit-ir -target %target-future-triple -min-runtime-version 5.11 %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop | %FileCheck %s
+// RUN: %target-swift-emit-ir -target %target-triple -min-runtime-version 5.9 %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop | %FileCheck %s --check-prefix=GXX
 
 // REQUIRES: objc_interop
 // UNSUPPORTED: OS=windows-msvc
@@ -45,3 +46,17 @@ testObjCMethodCall()
 // CHECK-NEXT: call void @llvm.trap()
 // CHECK-NEXT: unreachable
 // CHECK-NEXT: }
+
+// GXX: define {{.*}} @"$s4test0A14ObjCMethodCallyyF"() #[[#UWATTR:]] personality ptr @__gxx_personality_v0
+// GXX: invoke void {{.*}}@objc_msgSend
+// GXX-NEXT: to label %[[CONT1:.*]] unwind label %[[UNWIND1:.*]]
+// GXX-EMPTY:
+// GXX-NEXT: [[CONT1]]:
+// GXX:  ret
+// GXX-EMPTY:
+// GXX-NEXT: [[UNWIND1]]:
+// GXX-NEXT: landingpad { ptr, i32 }
+// GXX-NEXT:    catch ptr null
+// GXX-NEXT: call void @llvm.trap()
+// GXX-NEXT: unreachable
+// GXX-NEXT: }

test/Interop/Cxx/exceptions/trap-on-exception-irgen-itanium.swift

@@ -1,8 +1,10 @@
 // RUN: %empty-directory(%t)
 // RUN: split-file %s %t
 
-// RUN: %target-swift-emit-ir %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop | %FileCheck %s
-// RUN: %target-swift-emit-ir %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop -g | %FileCheck --check-prefix=DEBUG %s
+// RUN: %target-swift-emit-ir -target %target-future-triple -min-runtime-version 5.11 %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop | %FileCheck %s
+// RUN: %target-swift-emit-ir -target %target-future-triple -min-runtime-version 5.11 %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop -g | %FileCheck --check-prefix=DEBUG %s
+// RUN: %target-swift-emit-ir -target %target-triple -min-runtime-version 5.9 %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop | %FileCheck --check-prefix=GXX %s
+// RUN: %target-swift-emit-ir -target %target-triple -min-runtime-version 5.9 %t/test.swift -I %t/Inputs -enable-experimental-cxx-interop -g | %FileCheck --check-prefix=GXX %s
 
 // UNSUPPORTED: OS=windows-msvc
 
@@ -335,7 +337,7 @@ public func test() {
 // CHECK-NEXT: unreachable
 // CHECK-NEXT: }
 
-// CHECK: i32 @_swift_exceptionPersonality(...)
+// CHECK: i32 @_swift_exceptionPersonality(i32, i32, i64, ptr, ptr)
 
 // CHECK: define {{.*}} @"$s4test0A11MethodCallss5Int32VyF"() #[[#SWIFTUWMETA]] personality
 // CHECK: call swiftcc i32 @"$s4test8makeCInts5Int32VyF"()
@@ -502,3 +504,6 @@ public func test() {
 // DEBUG: ![[#DEBUGLOC_TRAP1]] = !DILocation(line: 0, scope: ![[#TRAPSCOPE:]], inlinedAt: ![[#DEBUGLOC_FREEFUNCTIONTHROWS1]])
 // DEBUG: ![[#TRAPSCOPE]] = distinct !DISubprogram(name: "Swift runtime failure: unhandled C++{{ / Objective-C | }}exception"
 // DEBUG: ![[#DEBUGLOC_TRAP2]] = !DILocation(line: 0, scope: ![[#TRAPSCOPE]], inlinedAt: ![[#DEBUGLOC_FREEFUNCTIONTHROWS2]])
+
+// GXX: __gxx_personality_v0
+// GXX-NOT: _swift_exceptionPersonality