Avoid record-inner constants in polymorphic definitions in Bali The Bali package needs to insert a record extension into a type class and define an associated polymorphic constant. There is no elegant way to do this. The existing approach was to insert every record extension into the type class, defining the polymorphic constant at each layer using inner operations created by the record package. Some of those operations have been removed. They can be replaced by use of record_name.extend if necessary, but we can also sidestep this altogether. The simpler approach here is to use defs(overloaded) once to provide a single definition for the composition of all the type constructors, which seems to be permitted. This gets us exactly the fact we need, with the cost that some types that were admitted to the type class have no definition for the constant at all.

Merge with changes from isabelle dev repository.

Initial response to feedback from Norbert, Makarius on record patch As Norbert recommended, the IsTuple.thy and istuple_support.ML files have been integrated into Record.thy and record.ML. I haven't merged the structures - record.ML now contains Record and IsTupleSupport. Some of the cosmetic changes Makarius requested have been made, including renaming variables with camel-case and run-together names and removing the tab character from the Author: line. Constants are defined with definition rather than constdefs. The split_ex_prf inner function has been cleaned up.

Branch merge for isabelle mainline updates.

Branch merge with updates from mainline isabelle.

Implement previous fix (don't duplicate ext_def) correctly.