Merge 'emit SetCookie after DropTable' from Glauber Costa

The SetCookie opcode is used, among other things, to notify the
transaction of schema changes. We are not issuing it on DropTable.
Without it, the transaction thinks the schema hasn't changed, and does
not update the schema of the connection back to the database.
SQLite will, of course, issue it:
35    DropTable      0     0     0     foo            0
36    SetCookie      0     1     2                    0
Unfortunately I don't have a unit test that breaks with this, because
the one that is supposed to break is having, let's put it this way,
bigger problems.

Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>

Closes #2249

core/translate/schema.rs

@@ -932,6 +932,13 @@ pub fn translate_drop_table(
         table_name: tbl_name.name.0,
     });
 
+    program.emit_insn(Insn::SetCookie {
+        db: 0,
+        cookie: Cookie::SchemaVersion,
+        value: schema.schema_version as i32 + 1,
+        p5: 0,
+    });
+
     //  end of the program
     program.epilogue(super::emitter::TransactionMode::Write);