Merge the `use` parts of the `no_std` branch. This reduces the diffs between master and the `no_std` branch, making it easier to maintain. Most of these changes are derived from patches by @lachlansneff in https://github.com/Cretonne/cretonne/tree/no_std.
This crate provides a straightforward way to create a
Cretonne IL function and fill it with
instructions translated from another language. It contains an SSA construction
module that provides convenient methods for translating non-SSA variables into
SSA Cretonne IL values via use_var and def_var calls.