Rollup merge of rust-lang#26144 - steveklabnik:static_doc_fix, r=alexcrichton

Fixes rust-lang#25851

I am 99% sure this is true for all `static`s and not just `static mut`, yes?

Author: steveklabnik

src/doc/trpl/const-and-static.md

@@ -64,7 +64,10 @@ unsafe {
 
 [unsafe]: unsafe.html
 
-Furthermore, any type stored in a `static` must be `Sync`.
+Furthermore, any type stored in a `static` must be `Sync`, and may not have
+a [`Drop`][drop] implementation.
+
+[drop]: drop.html
 
 # Initializing