Test failure: ilasm round-trip HugeField2

[BruceForstall]

With:

set COMPlus_TieredCompilation=0
set RunningIlasmRoundTrip=1

C:\h\w\968F0820\w\A48B0918\e>set PATH=C:\h\w\968F0820\p\dotnet;C:\python3.7.0\lib\site-packages\pywin32_system32;C:\python3.7.0\Scripts\;C:\python3.7.0\;C:\windows\system32;C:\windows;C:\windows\System32\Wbem;C:\windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Microsoft SQL Server\130\Tools\Binn\;C:\Users\runner\AppData\Local\Microsoft\WindowsApps 

C:\h\w\968F0820\w\A48B0918\e>dotnet C:\h\w\968F0820\p\xunit.console.dll JIT\jit64\JIT.jit64.XUnitWrapper.dll -parallel collections -nocolor -noshadow -xml testResults.xml -trait TestGroup=JIT.jit64.opt 
Microsoft.DotNet.XUnitConsoleRunner v2.5.0 (32-bit .NET 5.0.0-preview.6.20305.6)
  Discovering: JIT.jit64.XUnitWrapper
  Discovered:  JIT.jit64.XUnitWrapper
  Starting:    JIT.jit64.XUnitWrapper
    JIT\jit64\opt\cse\HugeField2\HugeField2.cmd [FAIL]
      
      Return code:      1
      Raw output file:      C:\h\w\968F0820\w\A48B0918\e\JIT\jit64\Reports\JIT.jit64\opt\cse\HugeField2\HugeField2.output.txt
      Raw output:
      BEGIN EXECUTION
      C:\h\w\968F0820\p\ildasm.exe /raweh /out=HugeField2.dasm.il HugeField2.dll
      C:\h\w\968F0820\p\ilasm.exe /output=HugeField2.asm.dll  HugeField2.dasm.il
      EXECUTION OF ILASM - FAILED 3
      Test Harness Exitcode is : 1
      To run the test:
      > set CORE_ROOT=C:\h\w\968F0820\p
      > C:\h\w\968F0820\w\A48B0918\e\JIT\jit64\opt\cse\HugeField2\HugeField2.cmd
      Expected: True
      Actual:   False
      Stack Trace:
        F:\workspace\_work\1\s\artifacts\tests\coreclr\Windows_NT.x86.Checked\TestWrappers\JIT.jit64\JIT.jit64.XUnitWrapper.cs(22159,0): at JIT_jit64._opt_cse_HugeField2_HugeField2_._opt_cse_HugeField2_HugeField2_cmd()
      Output:
        
        Return code:      1
        Raw output file:      C:\h\w\968F0820\w\A48B0918\e\JIT\jit64\Reports\JIT.jit64\opt\cse\HugeField2\HugeField2.output.txt
        Raw output:
        BEGIN EXECUTION
        C:\h\w\968F0820\p\ildasm.exe /raweh /out=HugeField2.dasm.il HugeField2.dll
        C:\h\w\968F0820\p\ilasm.exe /output=HugeField2.asm.dll  HugeField2.dasm.il
        EXECUTION OF ILASM - FAILED 3
        Test Harness Exitcode is : 1
        To run the test:
        > set CORE_ROOT=C:\h\w\968F0820\p
        > C:\h\w\968F0820\w\A48B0918\e\JIT\jit64\opt\cse\HugeField2\HugeField2.cmd
  Finished:    JIT.jit64.XUnitWrapper
=== TEST EXECUTION SUMMARY ===
   JIT.jit64.XUnitWrapper  Total: 145, Errors: 0, Failed: 1, Skipped: 0, Time: 738.446s

From Windows x86:

https://dev.azure.com/dnceng/public/_build/results?buildId=708755&view=ms.vss-test-web.build-test-results-tab&runId=21956288&resultId=103873&paneView=debug

[markples]

Fixed in #76590