[CodeGen] Add machine metadata graphs

Model ordered function-local metadata tuples with explicit embedded-IR and MachineFunction reference scopes. Preserve slot zero, distinct nodes, forward references, and cyclic graphs while verifying function-local closure and cloning the graph deterministically.

1 files changed, 4 insertions, 0 deletions

diff --git a/backend/lib/CodeGen/MachineFunctionCloner.cpp b/backend/lib/CodeGen/MachineFunctionCloner.cpp
index 2f99341..e12e33e 100644
--- a/backend/lib/CodeGen/MachineFunctionCloner.cpp
+++ b/backend/lib/CodeGen/MachineFunctionCloner.cpp
@@ -626,6 +626,10 @@ Expected<MachineFunctionCloneResult> cloneMachineFunction(const MachineFunction
   if (!Records)
     return std::unexpected(Records.error());
   Result.ClonedFunction->records() = std::move(*Records);
+  auto Metadata = Source.metadata().clone();
+  if (!Metadata)
+    return std::unexpected(Metadata.error());
+  Result.ClonedFunction->metadata() = std::move(*Metadata);
   Result.ClonedFunction->properties() = Source.properties();
   Result.ClonedFunction->attributes() = Source.attributes();
   auto DestinationVerification = MachineVerifier::verify(*Result.ClonedFunction, Target);