Replace macro backtraces with labeled local uses#35702

Merged

bors merged 3 commits intorust-lang:masterfrom

sophiajt:add_backtrace_labels

Aug 18, 2016

Commits on Aug 17, 2016

Fix merge conflict
Jonathan Turner
committed
Replace local backtrace with def-use, repair std macro spans
Jonathan Turner
committed
Rebase. Fix mutable iteration nit.
Jonathan Turner
committed