Change `false`, `pwd`, and `true` to substitutive built-ins

[magicant]

POSIX.1-2024 removed the three utilities from the list of utilities that are always found regardless of PATH. To reflect this change, we need to change their type from "mandatory" to "substitutive". The built-in types are defined in builtin.h and builtin.c.

[c0d3-br3ak9r]

I'd like to work on this!

[c0d3-br3ak9r]

I've replaced the definitions for these commands from BI_MANDATORY to BI_SUBSTITUTIVE in builtin.c. But I have some doubts regarding the tests.

Is it fine to remove the tests for these commands from builtins-p.tst and command-y.tst? And do they need to be added elsewhere?
Also in command-p.tst, false is being used to test command ignores function (mandatory built-in)? Should we replace it with other command?

[magicant]

Hi,

Here is a summary of expected updates in the tests:

• In builtins-p.tst:
  • The tests generated by the test_nonspecial_builtin_function_override function should be left as is.
  • The test cases intrinsic built-in {...} can be invoked without $PATH should be removed for the three built-ins.
• In command-y.tst:
  • The three built-ins should be removed from the test case describing mandatory built-ins (-V). Instead, they should be added to the test case describing substitutive built-in (-V).
• In command-p.tst:
  • The test case command ignores function (mandatory built-in) should be updated to use another mandatory built-in.