codegen: arrow-literal in class ctor body emits IR with missing @ sigil on lambda reference

[cs01]

Bug

An arrow-literal assigned to a field inside a class constructor body emits malformed LLVM IR: store i8* __lambda_N, ... missing the @ sigil. Clang rejects the IR.

Example shape:

class Foo {
  cb: (x: string) => void;
  constructor() {
    this.cb = (x) => console.log(x);  // ← codegen emits broken IR here
  }
}

Workaround used in lib/net.ts (PR #585): declare a module-level named function (e.g., _netNoopCb) and assign the reference: this.cb = _netNoopCb.

Impact

Blocks idiomatic class initialization with callback fields. Forces module-level helpers that bloat the lib surface.

Likely fix location

src/codegen/ — lambda name emission. Probably a one-character fix (missing @ prefix in the IR print step).

[cs01]

Fixed by #593 (merged to main). Arrow-literal assignment to class field inside ctor body now emits store i8* @__lambda_N, ... with the correct sigil. Test fixture tests/fixtures/classes/class-arrow-field-in-ctor.ts asserts the behavior.