Implement support for branch instruction operands.

PiperOrigin-RevId: 205666777
diff --git a/include/mlir/IR/Module.h b/include/mlir/IR/Module.h
index 8401252..b0b9c96 100644
--- a/include/mlir/IR/Module.h
+++ b/include/mlir/IR/Module.h
@@ -37,6 +37,8 @@
 
   // FIXME: wrong representation and API.
   // TODO(someone): This should switch to llvm::iplist<Function>.
+  // TODO(someone): we also need a symbol table for function names +
+  // autorenaming like LLVM does.
   std::vector<Function*> functionList;
 
   /// Perform (potentially expensive) checks of invariants, used to detect