[SharedCache] Fix crash when trying to deserialize a routines_command_64 which had not been serialized.

We will just return early, this is fine as the previous code would effectively do the same thing.

Author: emesare

view/sharedcache/core/MetadataSerializable.cpp

@@ -354,6 +354,10 @@ void Serialize(SerializationContext& context, const routines_command_64& value)
 void Deserialize(DeserializationContext& context, std::string_view name, routines_command_64& b)
 {
 	auto bArr = context.doc[name.data()].GetArray();
+	// Because we might open databases that had not previously serialized this, we must allow
+	// an empty array, otherwise we will crash!
+	if (bArr.Size() < 4)
+		return;
 	b.cmd = bArr[0].GetUint();
 	b.cmdsize = bArr[1].GetUint();
 	b.init_address = bArr[2].GetUint();

view/sharedcache/core/SharedCache.h

@@ -482,7 +482,7 @@ namespace SharedCacheCore {
 				.MSL(symtab),
 				.MSL(dysymtab),
 				.MSL(dyldInfo),
-				.MSL(routines64), // TODO: This supposedly caused a crash on some binary? Need a repro.
+				.MSL(routines64),
 				.MSL(functionStarts),
 				.MSL(moduleInitSections),
 				.MSL(exportTrie),