The new PrimaryMap replaces the primary EntityMap and the PrimaryEntityData
marker trait which was causing some confusion. We now have a clear
division between the two types of maps:
- PrimaryMap is used to assign entity numbers to the primary data for an
entity.
- EntityMap is a secondary mapping adding additional info.
The split also means that the secondary EntityMap can now behave as if
all keys have a default value. This means that we can get rid of the
annoying ensure() and get_or_default() methods ther were used everywhere
instead of indexing. Just use normal indexing now; non-existent keys
will return the default value.
A FuncCursor works a like a layout cursor, but it holds a reference to
the entire function and lets you re-borrow the function reference.
Rewrite the dominator tree unit tests with a FuncCursor instead of a
layout cursor to demonstrate the difference. It avoids the constrained
lifetimes of the layout cursor in the tests.
Add a new cursor module and define an EncCursor data type in it. An
EncCursor is a cursor that inserts instructions with a valid encoding
for the ISA. This is useful for passes generating code after
legalization.
Implement a builder interface via the new InstInserterBase trait such
that the EncCursor builders support with_result().
Use EncCursor in coalescing.rs instead of the layout cursor as a proof
of concept.