auto merge of #8455 : nikomatsakis/rust/issue-5762-objects-dralston-d, r=graydon

Fix #5762 and various other aspects of object invocation.

r? @graydon

Author: bors

src/librustc/back/abi.rs

@@ -46,7 +46,8 @@ pub static tydesc_field_take_glue: uint = 2u;
 pub static tydesc_field_drop_glue: uint = 3u;
 pub static tydesc_field_free_glue: uint = 4u;
 pub static tydesc_field_visit_glue: uint = 5u;
-pub static n_tydesc_fields: uint = 6u;
+pub static tydesc_field_borrow_offset: uint = 6u;
+pub static n_tydesc_fields: uint = 7u;
 
 // The two halves of a closure: code and environment.
 pub static fn_field_code: uint = 0u;

src/librustc/driver/driver.rs

@@ -785,7 +785,7 @@ pub fn build_session(sopts: @session::options,
 pub fn build_session_(sopts: @session::options,
                       cm: @codemap::CodeMap,
                       demitter: diagnostic::Emitter,
-                      span_diagnostic_handler: @diagnostic::span_handler)
+                      span_diagnostic_handler: @mut diagnostic::span_handler)
                    -> Session {
     let target_cfg = build_target_config(sopts, demitter);
     let p_s = parse::new_parse_sess_special_handler(span_diagnostic_handler,