As discussed on issue #4819, I have created four new traits: `Algebraic`, `Trigonometric`, `Exponential` and `Hyperbolic`, and moved the appropriate methods into them from `Real`.

~~~rust
pub trait Algebraic {
    fn pow(&self, n: Self) -> Self;
    fn sqrt(&self) -> Self;
    fn rsqrt(&self) -> Self;
    fn cbrt(&self) -> Self;
    fn hypot(&self, other: Self) -> Self;
}

pub trait Trigonometric {
    fn sin(&self) -> Self;
    fn cos(&self) -> Self;
    fn tan(&self) -> Self;
    fn asin(&self) -> Self;
    fn acos(&self) -> Self;
    fn atan(&self) -> Self;
    fn atan2(&self, other: Self) -> Self;
}

pub trait Exponential {
    fn exp(&self) -> Self;
    fn exp2(&self) -> Self;
    fn expm1(&self) -> Self;
    fn log(&self) -> Self;
    fn log2(&self) -> Self;
    fn log10(&self) -> Self;
}

pub trait Hyperbolic: Exponential {
    fn sinh(&self) -> Self;
    fn cosh(&self) -> Self;
    fn tanh(&self) -> Self;
}
~~~

There was some discussion over whether we should shorten the names, for example `Trig` and `Exp`. No abbreviations have been agreed on yet, but this could be considered in the future.

Additionally, `Integer::divisible_by` has been renamed to `Integer::is_multiple_of`.

…=llogiq

"Respect" enums in `interior_mutable_const`

fixes rust-lang#3962
fixes rust-lang#3825

Hello,

It might not be a good idea to submit another relatively large PR while I have an opened PR; but, I've finished this anyway. This may be able to wait for months.

Note: the code uses the MIR interpreter, which the author of rust-lang#3962 thought unlikely to be a solution. This might be over-engineering; but, I think it's important to be able to work with the 'http' crate (rust-lang#3825). (And, I don't want to write a MIR visitor)

---

changelog: fix a false positive in two `interior_mutable_const` lints where a constant with enums gets linted
even if it uses a clearly unfrozen variant

…ust-lang#14078)

Remove "Known problems" section for `borrow_interior_mutable_const`
since issue were fixed some time ago - rust-lang#6110, rust-lang#5812

changelog: none