[Test] Disable witness-layout-opts-irgen.swift, failing on 32-bit

Author: mikeash

test/Interop/Cxx/value-witness-table/witness-layout-opts-irgen.swift

@@ -7,8 +7,8 @@
 // to test them in the same file.
 // XFAIL: OS=windows-msvc
 
-// Failing on i386 simulator, disable for now. rdar://73829982
-// UNSUPPORTED: DARWIN_SIMULATOR=ios
+// Failing on 32-bit simulator, disable for now. rdar://73829982
+// REQUIRES: rdar73829982
 
 import WitnessLayoutOpts