Log Message:
devel/smake: Update to 1.7nb4

New features with AN-2024-03-21:
- RULES: add symlinks for avbarm/riscv/amd64 for NetBSD.
  Submitted by: Matthew Green.

- Remove the register keyword from C++ sources. This keyword has
  been removed from the C++ language with C++17 and provides no
  benefit on most toolchains. Discard the keyword from all C++
  sources to enable a build with the new standard.
  Submitted by: Dennis Clarke.