[pytorch] reorder tracer code in generated VariableTypes (#38308)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38308
This PR doesn't add any new functionality. The purpose of this PR
is to validate reordering tracing code in variable kernel doesn't break
anything (which is a prerequisite of stacked change of moving tracing
logic into a new dispatch backend).
And it will be easier to bisect in case it breaks something which is not
covered by tests.
Test Plan: Imported from OSS
Differential Revision: D21570685
Pulled By: ljk53
fbshipit-source-id: 616b6434326df8381fb6f07c7b9aadac86dd02b4
