bug: built-in function .name own-property undefined (Promise.race.name, Math.min.name, Array.isArray.name) — follow-up to #2060 #2144

Summary

A built-in function's name own-property is undefined. Promise.race.name, Math.min.name, etc. all return undefined where the spec requires the function's name. #2060 fixed .name for user-defined function declarations and expressions; it didn't populate .name for built-ins.

Repro

console.log(Promise.race.name);             // expect: "race"
console.log(Math.min.name);                 // expect: "min"
console.log(Array.isArray.name);            // expect: "isArray"
console.log(Object.getOwnPropertyDescriptor(Promise.race, "name"));
// expect: { value:"race", writable:false, enumerable:false, configurable:true }
function foo(){}; console.log(foo.name);    // control — #2060: "foo" ✓

Why it matters

built-ins/Function was 16% on the re-harvest, with 38× Cannot read … (reading 'name') — the dominant signature. Most of those trace to a separate gap (built-in proto methods being undefined, then .name of undefined throwing — tracked in the sibling issue filed alongside). Once that lands, the residual .name === undefined cases (tests that explicitly inspect a real built-in's name) all hit this gap. Also degrades assert.throws reporting, which prints expectedErrorConstructor.name for messages — any built-in Error constructor reports as undefined instead of TypeError / RangeError / etc.

Likely cause

Whatever populated name on user-defined function objects in #2060 needs to also run when the engine creates built-in function values (the per-intrinsic setup code for Promise.*, Math.*, Array.isArray, error constructors, etc.).

Surfaced by the #799 Test262 radar re-harvest. Follow-up to #2060. Part of #793.