Small cleanup for a couple of parseable interface tests

Addressing post-commit review feedback from @jrose-apple.

Author: slavapestov

test/ParseableInterface/inherited-generic-parameters.swift

@@ -3,10 +3,9 @@
 // RUN: %target-swift-frontend -typecheck %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
 // RUN: %FileCheck %s < %t/main.swiftinterface
 
-// RUN: %target-build-swift %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
-// RUN: %FileCheck %s < %t/main.swiftinterface
+// RUN: %target-swift-frontend -emit-module -module-name main -primary-file %s -emit-module-path %t/main~partial.swiftmodule -enable-library-evolution
 
-// RUN: %target-build-swift %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution -wmo
+// RUN: %target-swift-frontend -merge-modules %t/main~partial.swiftmodule -emit-module-path %t/main.swiftmodule -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
 // RUN: %FileCheck %s < %t/main.swiftinterface
 
 // This test makes sure that we substitute uses of the superclass's generic

test/ParseableInterface/where-clause.swift

@@ -3,10 +3,9 @@
 // RUN: %target-swift-frontend -typecheck %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
 // RUN: %FileCheck %s < %t/main.swiftinterface
 
-// RUN: %target-build-swift %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
-// RUN: %FileCheck %s < %t/main.swiftinterface
+// RUN: %target-swift-frontend -emit-module -module-name main -primary-file %s -emit-module-path %t/main~partial.swiftmodule -enable-library-evolution
 
-// RUN: %target-build-swift %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution -wmo
+// RUN: %target-swift-frontend -merge-modules %t/main~partial.swiftmodule -emit-module-path %t/main.swiftmodule -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
 // RUN: %FileCheck %s < %t/main.swiftinterface
 
 // CHECK: import Swift