Kuroko 1.3

[klange]

This ticket is a draft release notes and TODO list for Kuroko 1.3, the next major release. 1.3 will follow 1.2.5.

Features:

• [x] Optimized method invocation instructions
• [x] Cached methods for operators.
• [x] Loop/iterator optimizations.
• [x] else branches for for and while loops.
• [x] Support for = in f-string expressions.
• [x] Relative import statements.
• [x] Improved support for package modules.
• [x] Overloads for in-place binary operators (eg., __iadd__)
• [x] Arbitrary precision integers with the long type, with seamless switchover back and forth from int.
• [x] Added comparator methods for tuples and lists.
• [x] Support for exception contexts when an exception is raised in an except block.
• [x] raise ... from ... to set causes for exceptions.
• [x] Private identifier mangling rules within classes, following Python's rules.
• [x] Format specs in f-strings, __format__ implementations for strings and ints/longs.
• [x] __setattr__, __set_name__
• [x] Additional operators: unary +, infix @
• [x] Compiler concatenation of unalike string tokens (f-strings, r-strings, and regular strings)

Notable bug fixes:

• [x] Resolved several issues with memory allocation tracking for objects of flexible size.
• [x] Resolved an issue where value stacks referenced as argument lists in native functions could be reallocated, resulting in stale references.
• [x] Resolved various issues in which exceptions raised in nested managed execution could result in incorrect stack pointer offsets.