build: order smoke_test and dsymutil after strip - #36139

The unwrap regex `/\$\n {2}/g` doesn't match what `wrapLongLine()` in `scripts/build/ninja.ts` actually emits — continuations are ` $` + newline + **4** spaces, so a wrapped `foo $\n    bar` would unwrap to `foo   bar` (3 stray spaces) and the exact `.toBe()` assertions below would fail with a confusing whitespace diff. Currently latent (these edges are ~51-73 chars, under the 120-char wrap threshold), but `/ \$\n {4}/g` → `" "` would make the helper match its own docstring.

This is the fourth copy of `mockToolchain()` in `test/internal/` — near-identical helpers already exist in `macos-cross-config.test.ts`, `source-lints/webkit-prebuilt-url.test.ts`, and `source-lints/windows-cross-config.test.ts`. The copies are already drifting (this one had to add `hostCc`/`hostCxx` that the others lack), so it may be worth extracting a shared `mockToolchain()` into something like `test/internal/build-helpers.ts` and importing it in all four places. Non-blocking — test-only, an