gh-124351: Optimize Endianness Handling in ctypes Module

[Harikrishna-Srinivasan]

Code Review Comments

1. Global Variable Usage: The use of a global variable (_OTHER_ENDIAN) can lead to potential issues with state management and performance, as global lookups are generally slower than local variable accesses.

2. Redundant Checks: The _other_endian function repeatedly checks the type of typ, which can be inefficient if this function is called multiple times.

3. List Creation Overhead: In the __setattr__ method of _swapped_meta, creating a new list for fields can introduce unnecessary overhead, especially if no modifications are made.

• Issue: Optimize Endianness Handling in ctypes Module #124351

[ghost]

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[bedevere-app]

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

[skirpichev]

Please revert all unrelated changes, see examples.

Please also keep just one news entry, that describe actual changes.

[skirpichev]

@Harikrishna-Srinivasan-1, please read https://devguide.python.org/ first. Then please address review comments.