[release/9.0-staging] Fix System.Reflection.Emit `SetChecksum` creating invalid pdb by github-actions[bot] · Pull Request #110205

[release/9.0-staging] Fix System.Reflection.Emit `SetChecksum` creating invalid pdb by github-actions[bot] · Pull Request #110205 · dotnet/runtime

Backport of #110097 to release/9.0-staging

Fixes #110096.

/cc @steveharter @tgjones

Customer Impact

Customer reported

This is preventing the use of PDBs with source document checksums that allow, for example, the source .cs file to be verified it has not been altered.

Regression

This code was introduced in v9 in this PR which had the bug.

Testing

This PR added the test.

Risk

Low. The fix is straightforward and one LOC.