Mark two expensive tests with long_test

Author: gribozavr

test/IDE/print_stdlib.swift

@@ -1,5 +1,7 @@
 // Check interface produced for the standard library.
 //
+// REQUIRES: long_test
+//
 // RUN: %target-swift-frontend -parse %s
 // RUN: %target-swift-ide-test -print-module -module-to-print=Swift -source-filename %s -print-interface > %t.txt
 // RUN: FileCheck -check-prefix=CHECK-ARGC %s < %t.txt

validation-test/Driver/many-inputs.swift

@@ -16,3 +16,5 @@
 // RUN: (cd %t && %target-build-swift -emit-library ./*.swift -o ./libMultiFile)
 // RUN: nm %t/libMultiFile | FileCheck %t/check.txt
 
+// REQUIRES: long_test
+