The native sanitizer build chose the variants to compile by artifact path.
Since the runtime pack stores identical objects once, two variants of a
unit can share a path, so it compiled such a unit for both variants and
linked it twice (duplicate symbols in the sanitized native bootstrap).
selectedRuntimeUnits now returns each selected unit with its variant;
selectRuntimePackArtifacts and the sanitizer both use it.
Staging the native CLI's assets ran llvm-strip unconditionally and failed
on hosts without it. Without llvm-strip on PATH, tsc-ts now keeps its
symbols and the build prints a warning; the release hosts install LLVM.
Chris Tate
a758ff1b4e