libc/tests: add stdbit test framework and unit tests

[fuz]

Summary

This adds unit tests for all 70 functions in <stdbit.h>.

I'm sorry for the test framework, but it makes it so I don't
have to write 70 unit tests by hand.

Test Plan

This is the test plan for D53657.

[fuz]

• libc/tests/Makefile: use tab, not space for indent
• libc/tests/stdbit: remove - from /*-

[adrian]

absolutely amazing use of macros and included source files i love it

[des]

lib/libc/tests/stdbit/stdbit-test-framework.c

63

no longer needed

lib/libc/tests/stdbit/stdbit-test-kernel.c

40

47

[fuz]

lib/libc/tests/stdbit/stdbit-test-framework.c

63

If I remove ATF_TP_ADD_TCS, the tests fail to build (undefined symbol main). If I just remove the individual test cases ATF_TP_ADD_TC, then no unit tests end up defined. I am confused as to which part of this is “no longer needed.” Please clarify.

[fuz]

• fix formatting issues in stdbit unit tests

[fuz]

• use _WIDTH macros from C23 <limits.h> in stdbit unit tests, see D53825

[des]

I just remembered that you need to add an stdbit directory to etc/mtree/BSD.tests.mk:

--- a/etc/mtree/BSD.tests.dist
+++ b/etc/mtree/BSD.tests.dist
@@ -382,6 +382,8 @@
             ..
             ssp
             ..
+            stdbit
+            ..
             stdio
             ..
             stdlib

[fuz]

Thanks, this is something I always forget about.

[fuz]

• etc/mtree: add stdbit directory to etc/mtree/BSD.tests.mk

[markj]

Approved