empty_count false positive with PHFetchResult

[Noobish1]

New Issue Checklist

• Updated SwiftLint to the latest version
• I searched for existing GitHub issues

Describe the bug

The guard below triggers the empty_count rule however PHFetchResult doesn't actually have an isEmpty computed property so it's impossible to use it.

private var fetchResult = PHFetchResult<PHAsset>()

guard fetchResult.count > 0 else {
    return
}
``

##### Complete output when running SwiftLint, including the stack trace and command used

I'm running this in a Run Script Phase

```bash
set -e
set -o pipefail

"${SRCROOT}/SwiftLint/swiftlint" --quiet --strict | sed 's/warning:/error:/g'

Output

Empty Count Violation: Prefer checking `isEmpty` over comparing `count` to zero. (empty_count)

Environment

• SwiftLint version 0.33.1, portable version
• I'm not using nested config files

I'll include this anyway but I don't think it matters for this, I've replaced the names of my app/frameworks in the included bit.

disabled_rules:
    - identifier_name
    - private_over_fileprivate
    - redundant_string_enum_value
    - todo
opt_in_rules:
    - force_unwrapping
    - attributes
    - file_header
    - prohibited_super_call
    - closure_spacing
    - explicit_init
    - first_where
    - nimble_operator
    - overridden_super_call
    - private_outlet
    - redundant_nil_coalescing
    - fatal_error_message
    - explicit_top_level_acl
    - implicit_return
    - empty_count
    - array_init
    - closure_end_indentation
    - contains_over_first_not_nil
    - let_var_whitespace
    - literal_expression_end_indentation
    - operator_usage_whitespace
    - override_in_extension
    - quick_discouraged_call
    - quick_discouraged_focused_test
    - quick_discouraged_pending_test
    - single_test_class
    - sorted_first_last
    - unneeded_parentheses_in_closure_argument
    - explicit_acl
    - private_action
    - sorted_imports
    - yoda_condition
    - convenience_type
    - discouraged_optional_boolean
    - discouraged_optional_collection
    - empty_string
    - empty_xctest_method
    - fallthrough
    - file_name
    - lower_acl_than_parent
    - modifier_order
    - switch_case_alignment
    - unavailable_function
    - explicit_enum_raw_value
    - anyobject_protocol
    - implicitly_unwrapped_optional
    - closure_body_length
    - discouraged_object_literal
    - identical_operands
    - last_where
    - legacy_random
    - multiline_arguments
    - prohibited_interface_builder
    - toggle_bool
    - unused_import
    - unused_private_declaration
    - static_operator
    - redundant_type_annotation
    - nslocalizedstring_key
    - multiline_function_chains
    - multiline_literal_brackets
    - multiline_parameters
    - multiline_parameters_brackets
    - vertical_parameter_alignment_on_call
    - vertical_whitespace_closing_braces
    - vertical_whitespace_opening_braces
    - reduce_into
    - file_contents_order
    - type_contents_order
    - no_extension_access_modifier
included:
    - MyApp
    - MyAppFrameworks
type_contents_order:
    order:
        - type_alias
        - associated_type
        - subtype
        - case
        - [type_property, instance_property]
        - ib_outlet
        - ib_inspectable
        - initializer
        - type_method
        - [other_method, view_life_cycle_method]
        - [other_method, ib_action, subscript]
cyclomatic_complexity:
    ignores_case_statements: true
trailing_whitespace:
    ignores_empty_lines: true
colon:
    apply_to_dictionaries: false
line_length: 200 # I think I want 104 though
file_length:
    - 750 # warning
closure_body_length:
    - 30 # warning
function_body_length:
    - 200 # warning
type_body_length:
    - 600 # warning
type_name:
    excluded:
        - R # R.swift
        - image # R.swift
        - intern # R.swift
        - _R # R.swift
    min_length: 2 # only warning
    max_length: # warning and error
        warning: 60
file_name:
    excluded:
        - R.generated.swift
modifier_order:
    preferred_modifier_order:
        - acl
        - override
nesting:
    type_level:
        warning: 4
switch_case_alignment:
    indented_cases: true
function_parameter_count:
    warning: 7

[marcelofabri]

Duplicate of #827.