Pyjion

* PGC now observes and optimizes heap-allocated (user-defined) types
* Fixed a crash on certain recursive functions with PGC enabled

* Fixed macOS wheel name

* LOAD_ATTR is now optimized by for types that implement the tp_getattr by prehashing the names (OPT-15)
* JIT will emit a direct call to LOAD_ATTR tp_getattro/tp_getattr slots for builtin types
* macOS wheels are now compiled with Clang PGO
* PGC will only profile non heap-allocated types (ie not user specified types) as type objects could be deallocated between compilation cycles
* Reduced stack effect during frame calls/function calls
* Improved performance on function calls
* Py_MakePendingCalls will be called every 100 instructions (previously 10), configurable at compile-time through the `EMIT_PENDING_CALL_COUNTER` definition
* Updated to .NET 5.0.5 (5.0.202)
* Fixed a bug in PGC for large functions meaning they wouldn't be optimized
* Implemented PGC for BINARY_SUBSCR (OPT-5)
* Implemented PGC for STORE_SUBSCR (OPT-6)
* Implemented PGC for all inplace and regular binary operators (+, -, / etc) see OPT-13

* The compiler will now fail (and default back to CPython) if .NET emits a FAST_FAIL helper
* UNPACK_SEQUENCE is rewritten to be more efficient and use optimized paths for LIST and TUPLE types
* f-string (BUILD_STRING) is rewritten to be more efficient
* UNPACK_EX is rewritten to remove the requirement for dynamic heap allocation (and the stack canary) and leverage .NET compiler's dynamic eval stack
* PGC implemented for UNPACK_SEQUENCE
* PGC implemented for BINARY_SUBSCR
* PGC implemented for CALL_FUNCTION/OPT-14

* Added PGC emitter to first compile pass
* Drastically simplified the compilation process, resulting in a smaller call stack and allowing for more recursion (and better performance)
* Added a field to the pyjion.info() dictinary, `compile_result`, indicating cause of compilation failure (if failed), see `AbstractInterpreterResult` for enumerations
* Fixed a bug in pyjion.dump_native/pyjion.dis.dis_native disassembling the wrapper function
* Incompatible functions (those with async, yield keyword) are marked as incompatible early in the compilation process
* Fixed a bug in OPT-13 if the type changed under certain circumstances
* Arguments to a frame are now marked as volatile and requiring type guards for certain optimizations
* Any Python type passed as an argument is now available to be optimized by OPT-13, OPT-12
* Fixed a bug occuring on Linux and Windows in sre_parse._compile which caused a GuardStackException when doing an inline decref operation.
* Added an environment variable DOTNET_LIB_PATH to allow specifying the exact path to libclrjit

* Added OPT-13 (OPTIMIZE_TYPESLOT_LOOKUPS) to optimize the type slots for all binary operators and resolve the precedence at compile-time (only for known types)
* Added OPT-14 (OPTIMIZE_FUNCTION_CALLS) to optimize calls to builtin functions
* Optimize all frame locals by determining abstract types on compilation
* Bugfix: Fixed a crash on f-strings with lots (>255) arguments
* Bugfix: Will now skip all functions containing the use of `exec()` as it contains frame globals which are not supported
* Updated to .NET 5.0.3
* Updated the containers to Ubuntu 20
* Added fileobject abstract type
* Added enumerator abstract type
* Added code object abstract type
* Added integration tests for reference leaks for all binary operations (thanks amaeckelberghe)
* Added module type (thanks vacowboy75)