Removes all unstable and deprecated APIs prior to the 1.8 release. All APIs that
are deprecated in the 1.8 release are sticking around for the rest of this
cycle.
Some notable changes are:
* The `dynamic_lib` module was moved into `rustc_back` as the compiler still
relies on a few bits and pieces.
* The `DebugTuple` formatter now special-cases an empty struct name with only
one field to append a trailing comma.
under OpenBSD and Bitrig, it is an error to pass an empty argv
argument to execve(2). It results the test fail as execve(2) don't exec
and set errno to EINVAL.
instead, make argv with two arguments (in order to differenciate the
initial call, from the execve call).
Otherwise, the iterator and the functions for getting specific
environment variables might disagree, for environments like
FOOBAR
Variable names starting with equals sign are OK:
glibc only interprets equals signs not in the first position as
separators between variable name and variable value. Instead of skipping
them entirely, a leading equals sign is interpreted to be part of the
variable name.
