D18 — Position-independent build when bindings are on

Decision

With bindings on, the whole build is position independent (-fPIC -fno-semantic-interposition); bindings are off in sanitizer builds

Alternatives

A second PIC copy of the engine libraries; shared engine library

Reason

One set of objects; routing output and speed unchanged (C-BISCUIT: same board, 5.29 s vs 5.30 s); an instrumented extension cannot load into a plain interpreter