(backport from rev. 53935)

Don't use a fixed temporary name (gdbm).
Don't use our own temp name creation (dbm).

 (backport from rev. 53787)

 (backport from rev. 53785)

 (backport from rev. 53783)

when considering whether to rerun libffi configure.

Fixes #847665.

at position 0. (backport from rev. 53752)

 (backport from rev. 53697)

lib/python/config, on "linux" and "gnu" systems.

Applied patch 1124861.3.patch to solve bug #1124861: Automatically create pipes on Windows, if GetStdHandle fails. Backport from rev 53646.

the master should close the slave fd.

Added a test to test_pty.py that reads from the master_fd after doing
a pty.fork(); without the fix it hangs forever instead of raising an
exception.  (<crossing fingers for the buildbots>)

Backport from trunk rev. 53146.

 (backport from rev. 53603)