Package optimization allows bypassing resilience, but that assumes the memory layout of the

decl being accessed is correct. When this assumption fails due to a deserialization error
of its members, the use site accesses the layout with a wrong field offset, resulting in
UB or a crash. The deserialization error is currently not caught at compile time due to
LangOpts.EnableDeserializationRecovery being enabled by default to allow for recovery of some
of the deserialization errors at a later time. In case of member deserialization, however,
it's not necessarily recovered later on.

This PR tracks whether member deserialization had an error by recursively loading members and
checking for deserialization error, and fails and emits a diagnostic. It provides a way to
prevent resilience bypassing when the deserialized decl's layout is incorrect.

Resolves rdar://132411524

lib/Frontend/CompilerInvocation.cpp

@@ -1354,6 +1354,7 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
     }
   }
 
+  Opts.SkipDeserializationChecksForPackageCMO = Args.hasArg(OPT_ExperimentalSkipDeserializationChecksForPackageCMO);
   Opts.AllowNonResilientAccess =
       Args.hasArg(OPT_experimental_allow_non_resilient_access) ||
       Args.hasArg(OPT_allow_non_resilient_access) ||