Re-export common types in the cretonne::ir module.

Clients should not have to navigate the ir sub-modules to find commonly used
types.

src/libcretonne/isa/mod.rs

@@ -43,8 +43,7 @@
 pub mod riscv;
 
 use settings;
-use ir::dfg::DataFlowGraph;
-use ir::entities::Inst;
+use ir::{Inst, DataFlowGraph};
 
 /// Look for a supported ISA with the given `name`.
 /// Return a builder that can create a corresponding `TargetIsa`.

src/libcretonne/isa/riscv/mod.rs

@@ -5,8 +5,7 @@ pub mod settings;
 use super::super::settings as shared_settings;
 use super::Builder as IsaBuilder;
 use super::{TargetIsa, Encoding};
-use ir::dfg::DataFlowGraph;
-use ir::entities::Inst;
+use ir::{Inst, DataFlowGraph};
 
 #[allow(dead_code)]
 struct Isa {