Fix projection of sized field in unsized type

example/example.rs

@@ -196,3 +196,13 @@ fn str_wrapper_get(w: &StrWrapper) -> &str {
 fn i16_as_i8(a: i16) -> i8 {
     a as i8
 }
+
+struct Unsized(u8, str);
+
+fn get_sized_field_ref_from_unsized_type(u: &Unsized) -> &u8 {
+    &u.0
+}
+
+fn get_unsized_field_ref_from_unsized_type(u: &Unsized) -> &str {
+    &u.1
+}

src/common.rs

@@ -460,6 +460,12 @@ impl<'a, 'tcx: 'a> CPlace<'tcx> {
             }
             CPlace::Addr(base, extra, layout) => {
                 let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
+                let extra = if field_layout.is_unsized() {
+                    assert!(extra.is_some());
+                    extra
+                } else {
+                    None
+                };
                 CPlace::Addr(field_ptr, extra, field_layout)
             }
         }