79604f51be
When migrated to amd3 (possibly wiht newer CIRCT version), a new bug
shows up where storing both meta and valid into a single table doesn't
work, since writing meta writes {1'b0, meta} to the whole row of the
table overwriting the valid bit. Work this around by creating separate
tables for the meta and valid bits.
While at it, remove use of outdated NewSourceGenerator in VortexBank.