Default DCC to LWTOOLS

[DrPitre]

Summary

This updates DCC so the modern native build and default target workflow use LWTOOLS (lwasm/lwlink) instead of the legacy rma/rlink toolchain, while retaining a compatibility switch for the old flow.

The main behavioral change is that dcc file.c now emits LWTOOLS-compatible objects and links through lwlink by default. Existing -L usage remains accepted, and -R selects the legacy RMA/RLINK path.

What Changed

• Make LWTOOLS the default DCC backend

  • Add lwasm/lwlink driver support in dcc.
  • Pass -L through to dcc68 when generating LWTOOLS-compatible assembly.
  • Treat .o inputs as already-built LWTOOLS objects instead of assuming .r intermediates.
  • Link internally through lwlink so package makefiles can call dcc end-to-end.
  • Preserve legacy RMA/RLINK via new -R option.

• Improve native macOS buildability

  • Clean up host compiler assumptions and prototypes across the compiler tools.
  • Fix Unix system() status handling so failed child commands are reported correctly.
  • Update GNUmakefiles and warning flags where needed for current clang/GNU make builds.

• Add a localized macOS install script

  • New install-dcc-macos.sh builds and installs into $HOME/dcc by default.
  • Installs compiler binaries, definitions, help, startup object, and target libraries.
  • Keeps installation out of /usr/local unless the caller overrides PREFIX.

• Build target libraries for the LWTOOLS path

  • Add GNUmakefiles for KLibc sub-libraries built with lwasm/lwar.
  • Update the RMA-to-LWTOOLS conversion flow.
  • Fix chmod/chown assembly issues exposed by LWTOOLS.
  • Add qsort() to libc.a for packages that expect it.

Compatibility Notes

• dcc file.c now defaults to LWTOOLS output and linking.
• dcc -L file.c still works and is effectively explicit-default mode.
• dcc -R file.c requests the old RMA/RLINK flow.
• .r assumptions are intentionally removed from the default path; .o is the default object suffix for LWTOOLS builds.

Validation Performed

• Built the compiler tools natively on macOS with clang.
• Installed into $HOME/dcc using the new install script.
• Rebuilt and installed the LWTOOLS target libraries.
• Used the installed dcc to build NitrOS-9 third-party packages including ed, uemacs, and uucpbb through the new default LWTOOLS flow.

Review Focus

The biggest area to review is the default backend flip in Source/Compiler/DCC/dcc.c: argument handling, suffix handling, and the link command construction. The KLibc build changes are intended to support that flow without requiring package makefiles to know about lwasm/lwlink directly.