Add GeneratorDrop terminator to SMIR

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -282,7 +282,7 @@ fn rustc_terminator_to_terminator(
             unwind: rustc_unwind_to_unwind(unwind),
         },
         Yield { .. } => todo!(),
-        GeneratorDrop => todo!(),
+        GeneratorDrop => Terminator::GeneratorDrop,
         FalseEdge { .. } => todo!(),
         FalseUnwind { .. } => todo!(),
         InlineAsm { .. } => todo!(),

compiler/rustc_smir/src/stable_mir/mir/body.rs

@@ -42,6 +42,7 @@ pub enum Terminator {
         target: usize,
         unwind: UnwindAction,
     },
+    GeneratorDrop,
 }
 
 #[derive(Clone, Debug)]