017 record literal call arg subflow impl

// A record literal in argument position inside a pure-Koru subflow impl:
// `sum(env: { a: x, b: 2 })`. The same spelling emits correctly at flow head
// (labeled identifier and literal fields lower to `.{ .a = x, .b = 2 }`), but
// inside a subflow impl the argument literal is emitted verbatim —
// `.{ .env = { a: x, b: 2 } }` — and Zig rejects the bare `{ ... }` field
// value. The subflow body should lower call-arg record literals exactly like
// the flow-head path does.
~import std/io
const std = @import("std");
~tor sum { env: { a: i64, b: i64 } } -> i64
~proc sum|zig { return env.a + env.b; }

~tor one {} -> i64
~proc one|zig { return 1; }

~tor two {} -> i64
~two = one(): x |> sum(env: { a: x, b: 2 }): r -> r

~two(): s |> std/io:print.ln("{{ s:d }}")