Phase 3 of the native-default drive — the locally-verifiable items (CI and
rolling-bootstrap changes are deferred to Phase 4, where they become correct
once v0.12.0 is the rolling-bootstrap anchor):
- Help text now marks the backends explicitly: "qbe (deprecated) | native
(default)". QBE is retained as the e2e parity oracle and QBE-fixpoint guard;
removal is a later release.
- fixpoint-native-internal.sh now drives the FULL internal pipeline (internal
assembler + internal linker) against an all-external (gcc assemble + gcc link)
reference, instead of only differing on the assembler. Both internal tools are
now the default toolchain, so the conformance guard must exercise both. Header
comments updated to reflect that it guards the internal linker too and why it
stays a differential probe (the internal assembler buffers the whole object in
memory and OOMs on the compiler's own ~631k-line .s).
- language-rationale.adoc records the decision: native backend + internal
assembler + internal linker as the default toolchain (no external tools beyond
the C runtime startup objects), why QBE is kept-but-deprecated, and the
per-invocation escape hatches (--assembler external, --linker external,
--backend qbe, --incremental).
Verified: FIXPOINT_OK, NATIVE_FIXPOINT_OK, NATIVE_INTERNAL_OK; full suite
3541 tests / 0 failures on both the QBE-built and native-built test runners.