Fix sizeof tests for arm and x86

[AndyAyersMS]

On these tests the arm class layout happens to match the x64/arm64 layout and
is different than the x86 layout.

So, introduce arm specific test projects for these tests.

Also in the recent test build conversion one project was overlooked, so update
that project to work with this new scheme as well.

Closes #37470.

[AndyAyersMS]

cc @BruceForstall @jashook @sdmaclea

Git got carried away thinking there were some renames here so the diffs may look a bit clunky.

Will queue up outerloop tests shortly.

[sdmaclea]

LGTM.

I would have probably chosen a a different name for the new arm projects. Probably either *Target_arm or *Target_64bit_or_arm (renaming the target_64bit test). I am OK with this approach though.

[AndyAyersMS]

Two outerloop failures so far

Unable to precompile /__w/1/s/artifacts/tests/coreclr/Linux.arm64.Checked/Tests/Core_Root/Microsoft.CodeAnalysis.dll, exit code is 134.
Command-line: /__w/1/s/artifacts/bin/coreclr/Linux.arm64.Checked/x64/crossgen /Platform_Assemblies_Paths /__w/1/s/artifacts/tests/coreclr/Linux.arm64.Checked/Tests/Core_Root /__w/1/s/artifacts/tests/coreclr/Linux.arm64.Checked/Tests/Core_Root/Microsoft.CodeAnalysis.dll
Microsoft (R) CoreCLR Native Image Generator - Version 5.0.0-ci
Copyright (c) Microsoft Corporation.  All rights reserved.


Assert failure(PID 7396 [0x00001ce4], Thread: 7396 [0x1ce4]): Assertion failed 'kind == Overwrite' in 'Microsoft.Cci.MetadataWriter:PopulateMethodSemanticsTableRows():this' during 'Per block local var liveness' (IL size 578)

    File: /__w/1/s/src/coreclr/src/jit/jithashtable.h Line: 270
    Image: /__w/1/s/artifacts/bin/coreclr/Linux.arm64.Checked/x64/crossgen

Both look to be instances of #38496.

[AndyAyersMS]

A number of arm/arm64 test legs passed and there's nothing mode specific about the re-enabled tests, so am going to ignore the failures and merge.