Revert "Final merge conflict resolved"

This reverts commit 506865aed8f2775ec0782b2928ab4ce497df537b.
Revert "Error message change for register inst"

This reverts commit a2d12c91bee60bae255ac99824abea5c992954fa.
Revert "slowly fixing git conflicts..."

This reverts commit eebf646d852de9c46cd6828b2119baed27f976a8.