rustc: Initialize the drop flag with the new struct literal syntax. Closes #3172.

Author: pcwalton

src/rustc/middle/trans/base.rs

@@ -3515,6 +3515,12 @@ fn trans_struct(block_context: block, span: span, fields: ~[ast::field],
         }
     }
 
+    // Add the drop flag if necessary.
+    if ty::ty_dtor(block_context.tcx(), class_id).is_some() {
+        let llflagptr = GEPi(block_context, dest_address, ~[0, 0]);
+        Store(block_context, C_u8(1), llflagptr);
+    }
+
     // Now translate each field.
     let mut temp_cleanups = ~[];
     for fields.each |field| {

src/test/run-pass/struct-literal-dtor.rs

@@ -0,0 +1,8 @@
+struct foo {
+    x: ~str;
+    drop { #error["%s", self.x]; }
+}
+
+fn main() {
+    let _z = foo { x: ~"Hello" };
+}