Fix loop cloning for OSR

[BruceForstall]

Fix a previously unused piece of code to handle a loop cloning case
where the head block of a loop branches to the entry block.

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Issue Details

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Fix a previously unused piece of code to handle a loop cloning case
where the head block of a loop branches to the entry block.

Author:	BruceForstall
Assignees:	BruceForstall
Labels:	area-CodeGen-coreclr
Milestone:	-

[BruceForstall]

The code in question was unused, as the comment stated. The fix: remove simple C++ variable name shadow declaration :-)

[BruceForstall]

@AndyAyersMS PTAL
cc @dotnet/jit-contrib

[BruceForstall]

@AndyAyersMS Feel free to suggest or kick off appropriate OSR testing.

[AndyAyersMS]

/azp run runtime-jit-experimental

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[AndyAyersMS]

Note the experimental tests are seeing ARM64 failures because of #66924, so some failures are expected.

[BruceForstall]

@AndyAyersMS Can you advise if the failures in https://dev.azure.com/dnceng/public/_build/results?buildId=1679130&view=ms.vss-test-web.build-test-results-tab are "expected"? They are all arm64.

[AndyAyersMS]

@AndyAyersMS Can you advise if the failures in https://dev.azure.com/dnceng/public/_build/results?buildId=1679130&view=ms.vss-test-web.build-test-results-tab are "expected"? They are all arm64

Yeah, those look like the expected ones.