[FX] Fix python code having spurious newlines from placeholders

[ghstack-poisoned]

torch/fx/graph.py

@@ -619,6 +619,8 @@ def delete_unused_values(user : Node):
             not used in the remainder of the code are freed and the memory usage
             of the code is optimal.
             """
+            if user.op == 'placeholder':
+                return
             if user.op == 'output':
                 body.append('\n')
                 return
@@ -637,7 +639,7 @@ def emit_node(node : Node):
                 free_vars.append(f'{node.target}{maybe_type_annotation}{maybe_default_arg}')
                 raw_name = node.target.replace('*', '')
                 if raw_name != node.name:
-                    body.append(f'{node.name} = {raw_name}')
+                    body.append(f'{node.name} = {raw_name}\n')
                 return
             elif node.op == 'call_method':
                 assert isinstance(node.target, str)