How is a `cstr` made?

Decided

D-0039, settled by the language’s author: part of spec §18. Older text cites it as 18.39.

A string literal is one wherever a cstr is wanted, typed by its context as an untyped number is, and emitted as the C literal itself: it is zero-terminated static storage already, so nothing is allocated. "x" as cstr is the explicit spelling; c as str measures a C string. A runtime str has no terminating zero, so making a C string from one needs an owned copy, freed by its drop — which arrives with String (M12) and is spelled then. This replaces §5.3’s [PROPOSED] “conversion to cstr is explicit and may allocate”, which contradicted §15.1’s own InitWindow(…, "Dazzle") (§5.3)