Assertion `!opFlags.getMustExist() && "MustExist cannot be used with Proxy objects"' failed.

[7331akasokoan]

Commit 2af96b3 in static_h branch

PoC:

Object.setPrototypeOf(this, new Proxy({}, {
    has() {},
    getOwnPropertyDescriptor() {},
    get(target, prop, receiver) {
        'use strict';
        x = 30n;
    }
}));

a;

Command:

./hermes poc.js

Crash:

hermes: /home/test/hermes_workingdir/hermes/lib/VM/JSObject.cpp:1493: static CallResult<bool> hermes::vm::JSObject::putNamedWithReceiver_RJS(Handle<JSObject>, Runtime &, SymbolID, Handle<>, Handle<>, PropOpFlags, RuntimeModule *, SHUnit *, WritePropertyCacheEntry *): Assertion `!opFlags.getMustExist() && "MustExist cannot be used with Proxy objects"' failed.

[tmikov]

Seems like a duplicate of #379