Mark some executable_tests as such

Author: aschwaighofer

test/Generics/conditional_conformances_execute_smoke.swift

@@ -1,5 +1,7 @@
 // RUN: %target-run-simple-swift | %FileCheck %s
 
+// REQUIRES: executable_test
+
 // Smoke test to see that various conditional conformances correctly execute
 
 protocol P1 {

test/Interpreter/SDK/interpret_with_options.swift

@@ -4,6 +4,7 @@
 // RUN: %swift_driver -sdk %sdk -l%S/Inputs/libTestLoad.dylib %s | %FileCheck -check-prefix=WITH-LIB %s
 // RUN: cd %S && %swift_driver -sdk %sdk -lInputs/libTestLoad.dylib %s | %FileCheck -check-prefix=WITH-LIB %s
 // REQUIRES: OS=macosx
+// REQUIRES: executable_test
 
 import ObjectiveC
 

test/stdlib/Metal.swift

@@ -3,6 +3,8 @@
 // REQUIRES: objc_interop
 // UNSUPPORTED: OS=watchos
 
+// REQUIRES: executable_test
+
 import StdlibUnittest
 
 import Metal

test/stdlib/MetalKit.swift

@@ -3,6 +3,8 @@
 // REQUIRES: objc_interop
 // UNSUPPORTED: OS=watchos
 
+// REQUIRES: executable_test
+
 import StdlibUnittest
 
 import Metal