Add lints to encourage use of specialized assert macros

[Reisz]

What it does

Detect assert!(a == b) and assert!(a != b) and suggest using assert_eq! or assert_ne! respectively.

Should probably apply to debug_assert! as well.

Advantage

• The specialized asserts provide more info in their error messages

Drawbacks

No response

Example

assert!(fib(6) == 8);

Could be written as:

assert_eq!(fib(6), 8);

[nyurik]

I wonder if we should extend the bool_assert_comparison lint.

The description actually matches what is being proposed:

This lint warns about boolean comparisons in assert-like macros.

[nyurik]

@rustbot claim