Rollup merge of #114977 - kpreid:modulo, r=thomcc

Add `modulo` and `mod` as doc aliases for `rem_euclid`.

When I was learning Rust I looked for “a modulo function” and couldn’t find one, so thought I had to write my own; it wasn't at all obvious that a function with “rem” in the name was the function I wanted. Hopefully this will save the next learner from that.

However, it does have the disadvantage that the top results in rustdoc for “mod” are now these aliases instead of the Rust keyword, which probably isn't ideal.

library/std/src/f64.rs

@@ -323,6 +323,7 @@ impl f64 {
     /// // limitation due to round-off error
     /// assert!((-f64::EPSILON).rem_euclid(3.0) != 0.0);
     /// ```
+    #[doc(alias = "modulo", alias = "mod")]
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[inline]