The wcc test drivers ran `ww build <bare-/tmp src>` with no -o, so the
compiler's <stem>.sepwork scratch landed beside the source and was never
cleaned: unbounded /tmp growth (2195 stale dirs observed) that fills tmpfs
and fabricates phantom test failures + silent harness aborts, and for
in-repo fixture builds leaked .sepwork into the tracked tree.
Each leaking build now writes its source + output inside a per-invocation
tmpdir, passes -o <tmpdir>/<stem> so the .sepwork lands inside it, and
rm -rf's the tmpdir on every exit path -- including fopen-fail and the
expected-fail reject builds (scratch is mkdir'd before the build can fail).
`ww run` and explicit-`-o`/byte-id helpers are left as-is; the 990/993
byte-id comparison logic is byte-for-byte unchanged.
Two items filed separately (this commit holds the no-Makefile / no-main.c
rail):
- #13: a stale <src>.s byte-id readback (749) silently no-ops since
separate-compile emits .s to <ostem>.sepwork/__root.s; documented inline.
- #14: build-system Makefile recipes build selfhost/cmd/*/main.ww with no
-o and leak main.sepwork in-tree (bounded, gitignored; own commit).
One concern -- sepwork leak hygiene -- across 228 drivers; uniform
transform applied per-file and two-round reviewed. make test: all 402
passed, zero net-new /tmp scratch, zero test-driven in-repo .sepwork.
cstage rejects a binop whose two integer operands have different
types (e.g. int vs i32 from len()); wwstage accepted it, miscompiling
under no-implicit-promotion. Align wwstage UP: unifyarith now chases
aliases and loud-rejects an integer-type mismatch, routing the
ordered-comparison ops through the same path with the error message
threaded on `e`. Per the user's no-implicit-promotion decision.
Scope carve-outs: EQ/NEQ stay out of the reject (#34, the comparison
operators keep their own widening rule) and a rune literal is exempt
(#35, N_RUNELIT is still untyped at this point). Adds the 29-case
test/wcc/949_intbinop_mismatch.c and its Makefile wiring.
