Pyjion

* Fixed a crash bug where CPython checks recursion depth from ceval state, which may not be set
* Implemented a faster check for recursion depth
* Fixed a bug on LOAD_CLOSURE operator not being set
* Fixed OPT-2 on Windows and Linux
* Fixed a bug where the wrong CIL opcode was being used to subtract values, would throw an overflow error and fail back into EFD.
* Implemented the .NET EE exception handlers for guard stack canaries, overflow errors, and null reference exceptions
* Implemented a more efficient case of ld_i(1)
* Corrected cases of ob_refcnt to use 64-bit signed integers
* No longer print error messages on release code for unimplemented .NET EE methods
* Fixed a bug on the incorrect vtable relative field being set
* Fixed a bug where tracing and profiling would be emitted even when not explicitly enabled
* .NET Exceptions are transferred into Python exceptions at runtime

* Added an optimization (OPT-1/OPTIMIZE_IS) to inline the "is"/ "is not" statement into a simple pointer comparison with jump statement. Compiles to inline machine code instead of a method call
* Added an optimization (OPT-2/OPTIMIZE_DECREF) to decrement the refcount without a method call, when the object refcount is >1 and then call _Py_dealloc if the ref count becomes 0. Replaces the previous method call
* Windows now uses the system page size instead of the default value of 1MB

* Added support for .NET 5.0.1
* Implemented a CIL modulus emitter

* Added support for profiling compiled functions by enabling profiling (`pyjion.enable_profiling()`)
* Added support for profiling C function calls, returns and exceptions
* Implemented a faster call path for functions and methods for 5-10 arguments
* Fixed a bug where the page size defaulted to 0 in the .NET EE, which caused a failed assertion (and fails to compile the function), would fix a large % of functions that previously failed to compile

* Added support for debugging compiled functions and modules by enabling tracing (`pyjion.enable_tracing()`)
* Added support for debugging to catch unhandled/handled exceptions at runtime when tracing is enabled
* Added support for opcode-level tracing
* Fixed a bug on executing Pyjion with pydevd (VScode/PyCharm debugger) would cause the Python process to crash because of a doubly-freed code object (7)

* Added a WSGI middleware function to enable Pyjion for Flask and Django (67)
* Fix a bug on dictionary merging for mapping types incorrectly raising a type error (66)