Add an Opcode::constraints() method which returns an OpcodeConstraints object.
This object provides information on instruction polymorphism and how many
results is produced.
Generate a list of TypeSet objects for checking free type variables. The type
sets are parametrized rather than being represented as fully general sets.
Add UniqueTable and UniqueSeqTable classes to the meta code generator. Use for
compressing tabular data by removing duplicates.
This will eventualy be used for add-with-carry and add-with-overflow type
instructions. For now it only serves as a representative of instruction formats
that have multiple_results=True and boxed_storage=False at the same time.
Accessors for shared fields and multiple results can be generated automatically.
Add a 'boxed_storage' flag to the instruction format definitions to enable
generated code to access 'data'.
These two enums must have identical variants. One is generated from the
instruction formats in meta/cretonne/formats.py, the other defines the contents
of an instruction.
Emit a conversion from InstructionData to InstructionFormat which also serves
to verify the correspondence. Rustc will error is the match is not complete.
Avoid gathering too much code in repr.rs.
The `entities` module contains entity reference types, and the `instructions`
module contains instruction opcodes and formats.
