* Clarify how arguments are cast
* Limited C API version 3.11 no longer casts pointer arguments
* No longer remove return values
* Require to not change the return type
* Don't change macros having multiple return types
* Elaborate the Abstract
* Add "Misnesting" example
* The return value has already been removed in the public C API macros
* Clarify that converting Py_TYPE() macro was an incompatible change
* Don't convert l-value macros
* Add "Examples of duplication of side effects" section
* Remove the gcc -O0 versus gcc -Og benchmark: it's not relevent for
this PEP.