Issue #26592: _warnings.warn_explicit() now tries to import the warnings module
(Python implementation) if the source parameter is set to be able to log the
traceback where the source was allocated.
Issue #26604:
* Add a new optional source parameter to _warnings.warn() and warnings.warn()
* Modify asyncore, asyncio and _pyio modules to set the source parameter when
logging a ResourceWarning warning
Issue #26567:
* Add a new function PyErr_ResourceWarning() function to pass the destroyed
object
* Add a source attribute to warnings.WarningMessage
* Add warnings._showwarnmsg() which uses tracemalloc to get the traceback where
source object was allocated.
Issue #26568: add new _showwarnmsg() and _formatwarnmsg() functions to the
warnings module.
The C function warn_explicit() now calls warnings._showwarnmsg() with a
warnings.WarningMessage as parameter, instead of calling warnings.showwarning()
with multiple parameters.
_showwarnmsg() calls warnings.showwarning() if warnings.showwarning() was
replaced. Same for _formatwarnmsg(): call warnings.formatwarning() if it was
replaced.
The concept of .pyo files no longer exists. Now .pyc files have an
optional `opt-` tag which specifies if any extra optimizations beyond
the peepholer were applied.
instead of creating temporary Unicode string objects
Add also more identifiers in pythonrun.c to avoid temporary Unicode string
objets for the interactive interpreter.
