Fixed doc regarding Drop and static

Types implementing `Drop` are allowed in `static` and `const` definitions since
rust 1.22.0.

first-edition/src/const-and-static.md

@@ -64,17 +64,22 @@ unsafe {
 
 [unsafe]: unsafe.html
 
-Furthermore, any type stored in a `static` must be `Sync`, and must not have
-a [`Drop`][drop] implementation.
-
-[drop]: drop.html
+Furthermore, any type stored in a `static` must be `Sync`.
 
 # Initializing
 
 Both `const` and `static` have requirements for giving them a value. They must
 be given a value that’s a constant expression. In other words, you cannot use
 the result of a function call or anything similarly complex or at runtime.
 
+# Dropping
+
+Types implementing [`Drop`][drop] are allowed in `const` and `static`
+definitions. Constants are inlined where they are used and are dropped
+accordingly. `static` values are not dropped.
+
+[drop]: drop.html
+
 # Which construct should I use?
 
 Almost always, if you can choose between the two, choose `const`. It’s pretty