The native PDB writer has a size limit of 0x10000 for calls to ISymUnmanagedWriter::SetSymAttribute. The writer does not enforce this limit on calls to SetSymAttribute but rather in CloseMethod where it returns E_OUTOFMEMORY. That leads to us emitting errors like

error CS0041: Unexpected error writing debug information -- 'Insufficient memory to continue the execution of the program'

That is very difficult for customers and us to debug. To help with root causing these problems we should emit a better error in the compiler when we hit this limit. Specifically the error should take into account the 0x10000 limit and issue an error message that includes the name of the method that was being emitted when the limit was hit.

This has come up two times now: #73447 and an internal feedback ticket. Having this better error would've saved us significant time in tracking down the problem.