Tests: Factor unavailable protocol conformance tests into separate file.

Author: tshortli

test/IRGen/unavailable_decl_optimization.swift

@@ -147,17 +147,6 @@ public class C<T> {
   deinit {}
 }
 
-public protocol P {
-  func requirement()
-}
-
-@available(*, unavailable)
-extension S: P {
-  // CHECK-NO-STRIP: s4Test1SV11requirementyyF
-  // CHECK-STRIP-NOT: s4Test1SV11requirementyyF
-  public func requirement() {}
-}
-
 // MARK: -
 
 // MARK: UnavailableEnum

test/IRGen/unavailable_decl_optimization_conformance.swift

@@ -0,0 +1,26 @@
+// RUN: %target-swift-frontend -parse-as-library -module-name Test -validate-tbd-against-ir=missing %s -emit-ir | %FileCheck %s --check-prefixes=CHECK,CHECK-NO-STRIP
+
+// RUN: %target-swift-frontend -parse-as-library -module-name Test -validate-tbd-against-ir=missing -unavailable-decl-optimization=complete %s -emit-ir | %FileCheck %s --check-prefixes=CHECK,CHECK-STRIP
+
+// CHECK-NO-STRIP: s4Test1SVAA1PAAMc
+// CHECK-STRIP-NOT: s4Test1SVAA1PAAMc
+
+// CHECK-NO-STRIP: s4Test1SVAA1PAAWP
+// CHECK-STRIP-NOT: s4Test1SVAA1PAAWP
+
+// CHECK-NO-STRIP: s4Test1PMp
+// CHECK-STRIP-NOT: s4Test1PMp
+
+@available(*, unavailable)
+public protocol P {
+  func requirement()
+}
+
+public struct S {}
+
+@available(*, unavailable)
+extension S: P {
+  // CHECK-NO-STRIP: s4Test1SV11requirementyyF
+  // CHECK-STRIP-NOT: s4Test1SV11requirementyyF
+  public func requirement() {}
+}