Rollup merge of #46156 - SimonSapin:patch-14, r=withoutboats

Document the size of bool

src/libcore/mem.rs

@@ -189,6 +189,7 @@ pub fn forget<T>(t: T) {
 /// Type | size_of::\<Type>()
 /// ---- | ---------------
 /// () | 0
+/// bool | 1
 /// u8 | 1
 /// u16 | 2
 /// u32 | 4