057 build config basic

// Test: ~[build("flag")]std/build:config { ... } compiles cleanly.
//
// This is the canonical idiom for setting build-time configuration
// (cross-compilation target, etc.) gated on a --build flag.
//
// REGRESSION: the annotation `build("flag")` contains a literal `"` that
// must be escaped when serialized into Zig string literals during
// `backend_output_emitted.zig` emission. Without escaping, the generated
// Zig was `"build("flag")"` and failed to parse.

~import std/build

~[build("native")]std/build:config {
    "target": "x86_64-linux-gnu"
}

~pub event main { }

~proc main|zig {
    const x: u32 = 42;
    _ = x;
}