Auto merge of rust-lang#3483 - RalfJung:drop, r=RalfJung

add test for Drop terminator on non-drop type

Fixes rust-lang/miri#2737

src/tools/miri/tests/pass/drop_type_without_drop_glue.rs

@@ -0,0 +1,21 @@
+#![feature(custom_mir, core_intrinsics, strict_provenance)]
+use std::intrinsics::mir::*;
+
+// The `Drop` terminator on a type with no drop glue should be a NOP.
+
+#[custom_mir(dialect = "runtime", phase = "optimized")]
+fn drop_in_place_with_terminator(ptr: *mut i32) {
+    mir! {
+        {
+            Drop(*ptr, ReturnTo(after_call), UnwindContinue())
+        }
+        after_call = {
+            Return()
+        }
+    }
+}
+
+pub fn main() {
+    drop_in_place_with_terminator(std::ptr::without_provenance_mut(0));
+    drop_in_place_with_terminator(std::ptr::without_provenance_mut(1));
+}