Fix bit initializer which was one bit too long, but worked so long as we silently dropped the leading 0
Fix bit initializer which was one bit too long, but worked so long as we silently dropped the leading 0
Add a better error message when failing to assign one tablegen value to another

This is currently for assigning from one bit init to another.  It can easily be extended to other types.

Test to follow soon in another patch.
Don't fail tablegen immediately after failing to set a value.

Instead allow the variable to be declared, but don't attach an initializer. This allows more than a single error to be emitted before we exit.

Test case to follow soon in another patch.