- Add another canonicalize pass after lowering
 - Fix typification of array decl RHS
 - Fix: LowerToC did not descend into PsBufferAcc index args

 - Make freeze emit `PsBufferAcc`s
 - Typify `PsBufferAcc`s
 - Implement `LowerToC`
 - Subsume `EraseAnonStructs` into `LowerToC`

 - Remove subclasses of PsSymbol
 - Introduce symbol properties to attach information to symbols
 - Refactor `PsLinearizedArray` into `PsBuffer`
 - Introduce new `memory` submodule, move `PsSymbol`, `PsBuffer` and associated machinery there
 - Refactor PsBuffer constructor to always take indexing and pointer symbols from the outside
 - Update `KernelCreationContext` to create field buffers according to new API
 - Add tests for symbol properties; extend buffer creation tests

Revised Array Modelling & Memory Model

See merge request !420

Clarify semantics of fancy integer division functions.

See merge request !417

Improve freezing of additions

See merge request !415

Freeze casts of bare constants to typed PsConstantExprs

See merge request !411

Refactor Field Indexing Symbols

See merge request !408

Some minor internal and API fixes

See merge request !410

Various GPU-related and some general fixes.

See merge request !405

Change symbol typification: Infer unknown LHS data types from RHS

See merge request !407

Fundamental GPU Support

See merge request !384

API Backward Compatibility and Deprecations

See merge request !402

Revert previous front-end API changes + Cherry-pick fixes from master

See merge request !401

Extensions and fixes to the type system

See merge request !400