testsuite: Add compile-fail test for #5883
testsuite: Test for #6153, closes #6153
remove non-portable sed invocation as brson says we no longer have clang in tree.
librustc: Remove a bunch of `@` boxes from `Match`.

This will be needed to add `'static` bounds to `@`.
auto merge of #7863 : catamorphism/rust/issue-5883, r=catamorphism
auto merge of #7868 : pnkfelix/rust/issue6929-remove-bogus-sed-invoke-from-configure, r=brson

... in tree.

Fix #6929
auto merge of #7871 : pcwalton/rust/de-at-match, r=brson

This will be needed to add `'static` bounds to `@`.

r? @nikomatsakis
Ast spanned<T> refactoring, renaming: crate, local, blk, crate_num, crate_cfg.

`crate => Crate`
`local => Local`
`blk => Block`
`crate_num => CrateNum`
`crate_cfg => CrateConfig`

Also, Crate and Local are not wrapped in spanned<T> anymore.
De-spanned<T> and renamed ast::field (now ast::Field)