False positive for use_is_even_rather_than_modulo

[JaffaKetchup]

Describe the issue
In a constant expression, the use of x % 2 == 0 is a valid constant expression (assuming x is const), however .isEven is not.

To Reproduce

Example 1:

void main() {
    const x = 1;
    const e = x % 2 == 0; // Working, lint thrown
}

void main() {
    const x = 1;
    const e = x.isEven; // Compilation error, lint not thrown
}

Example 2:

class Example {
	const Example(int x) : assert(x % 2 == 0); // Working, lint thrown
}

class Example {
	const Example(int x) : assert(x.isEven); // Compilation error, lint not thrown
}

Expected behavior
use_is_even_rather_than_modulo should not be thrown when the surroundings are const.

This may also apply to other lints that apply similar suggestions: they should all be const-aware.

[srawlins]

Fixed with dart-lang/sdk@4c888ab