Just changing the arguments of a custom attribute constructor should generate
an update to the CustomAttributes table with the same parent and .ctor.  That
kind of change should be allowed by Mono and CoreCLR

unchanged.

Allows updates to the constructor arguments (or property values)

Add a bool array on the base image to keep track of whether each table had any
row modifications (as opposed to row additions) in any generation.

If there was a modification, take the slow path in mono_image_effective_table
even if the index we're looking at is in the base image.

Update hot_reload_effective_table_slow so that if there was a modified row, we
look at all the deltas to see if there's an even later update to that
row.  (When there are only additions, keep same behavior as before - only look
as far as the generation that added the row we wanted to find).

Also refine the assertion in hot_reload_relative_delta_index to properly
account for EnCMap entries that correspond to modifications - in that case we
might stop searching a metadata delta before we hit the end of the table if the
EnCmap entries start pointing to rows that are past the one we wanted to look
up.

Check that we get the updated custom attribute string property value.

Mono can now deal with the custom attributes modifications that Roslyn emits