Don't imply function pointers are references

Co-authored-by: David Tolnay <dtolnay@gmail.com>

Author: poliorcetics

src/libcore/mem/mod.rs

@@ -583,7 +583,7 @@ pub const fn needs_drop<T>() -> bool {
 ///
 /// There is no guarantee that an all-zero byte-pattern represents a valid value
 /// of some type `T`. For example, the all-zero byte-pattern is not a valid value
-/// for reference types (`&T`, `&mut T` and functions pointers). Using `zeroed` on
+/// for reference types (`&T`, `&mut T`) and functions pointers. Using `zeroed` on
 /// such types on such types causes immediate [undefined behavior][ub] because
 /// [the Rust compiler assumes][inv] that there always is a valid value in a
 /// variable it considers initialized.
@@ -613,7 +613,7 @@ pub const fn needs_drop<T>() -> bool {
 /// use std::mem;
 ///
 /// let _x: &i32 = unsafe { mem::zeroed() }; // Undefined behavior!
-/// let _y: fn() = unsafe { mem::zeroed() }; // And again !
+/// let _y: fn() = unsafe { mem::zeroed() }; // And again!
 /// ```
 #[inline(always)]
 #[stable(feature = "rust1", since = "1.0.0")]