Add a few convenient helpers to print error and warning messages.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
Changes in v2:
- Fix program_invocation_name test to handle test execution as /init
- Drop already applied patches
- Link to v1: https://patch.msgid.link/20260311-nolibc-err-h-v1-0-735a9de7f15d@weissschuh.net

---
Thomas Weißschuh (2):
      tools/nolibc: add support for program_invocation_{,short_}name
      tools/nolibc: add err.h

 tools/include/nolibc/Makefile                |  1 +
 tools/include/nolibc/crt.h                   | 26 ++++++++
 tools/include/nolibc/err.h                   | 91 ++++++++++++++++++++++++++++
 tools/include/nolibc/errno.h                 |  2 +
 tools/include/nolibc/nolibc.h                |  1 +
 tools/testing/selftests/nolibc/nolibc-test.c | 33 ++++++++++
 6 files changed, 154 insertions(+)
---
base-commit: 745dadd6d3d984feafb96f27b60d74b29ade4957
change-id: 20260311-nolibc-err-h-df36a75dddf8

Best regards,
-- 
Thomas Weißschuh <linux@weissschuh.net>