index using object (without start and end) should always emit an error

[itchyny]

Describe the bug
Indexing with an object should emit an error but does not against null.

To Reproduce

 % echo 'null' | jq '.[{}]'
null
 % echo '{}' | jq '.[{}]'
jq: error (at <stdin>:1): Cannot index object with object
 % echo 'null' | jq '.[[]]'
jq: error (at <stdin>:1): Cannot index object with array
 % echo '{}' | jq '.[[]]'
jq: error (at <stdin>:1): Cannot index object with array

The first case should be an error as well

Expected behavior

 % echo 'null' | jq '.[{}]'
jq: error (at <stdin>:1): Cannot index null with object

Also echo 'null' | jq '.[[]]' should print Cannot index null with array.

Environment (please complete the following information):

• OS and Version: macOS
• jq version: jq-master-50a7022

Additional Context
The path function does not emit an error quickly for this case so this function can return an invalid object entry as a path (an element in a path should be either a number, a string or an object with start and end).

 % echo 'null' | jq 'path(.[{"x":42}])'
[
  {
    "x": 42
  }
]
 % echo 'null' | jq '.[{"x":42}] = 1'
jq: error (at <stdin>:1): Start and end indices of an array slice must be numbers

This is a case which shows that null | path(.X) succeeds but null | .X = 1 fails.