Set attributes containing antiquotation in its name are ignored when there is a preceding definition

[coord-e]

Describe the bug

Attributes are unexpectedly ignored by Nix parser when there is a preceding definition of the set and the attribute name contains antiquotation.

Steps To Reproduce

minimal reproducible example:

# bug.nix
{
  set.name1 = {
    enable = true;
  };
  set = {
    "${"name2"}" = {
      enable = true;
    };
  };
}

parsing bug.nix only returns name1 as below:

$ nix-instantiate --parse bug.nix
{ set = { name1 = { enable = true; }; }; }

Expected behavior

parsing bug.nix expected to return both name1 and name2

nix-env --version output

$ nix-env --version
nix-env (Nix) 2.7.0

Additional context

this only happens when the attribute name contains antiquotation:

# parse: { set = { name1 = { enable = true; }; name2 = { enable = true; }; name3 = { enable = true; }; }; }
{
  set.name1 = {
    enable = true;
  };
  set = {
    # ok
    name2 = {
      enable = true;
    };
    # ok
    "name3" = {
      enable = true;
    };
    # ng
    "${"name4"}" = {
      enable = true;
    };
  };
}

this happens regardless of how the preceding set is defined:

# parse: { set = { name1 = { enable = true; }; }; }
{
  set = {
    name1 = {
      enable = true;
    };
  };
  set = {
    "${"name2"}" = {
      enable = true;
    };
  };
}

# parse: { set = { name1 = { enable = true; }; }; }
{
  set.name1.enable = true;
  set = {
    "${"name2"}" = {
      enable = true;
    };
  };
}

# parse: { set = { }; }
{
  set = {};
  set = {
    "${"name2"}" = {
      enable = true;
    };
  };
}