rustc_back: move LinkerFlavor, PanicStrategy, and RelroLevel to target.

Author: irinagpopa

src/librustc/ich/impls_misc.rs

@@ -20,7 +20,7 @@ impl_stable_hash_for!(enum ::session::search_paths::PathKind {
     All
 });
 
-impl_stable_hash_for!(enum ::rustc_back::PanicStrategy {
+impl_stable_hash_for!(enum ::rustc_back::target::PanicStrategy {
     Abort,
     Unwind
 });

src/librustc/middle/dependency_format.rs

@@ -69,7 +69,7 @@ use ty::TyCtxt;
 use middle::cstore::{self, DepKind};
 use middle::cstore::LinkagePreference::{self, RequireStatic, RequireDynamic};
 use util::nodemap::FxHashMap;
-use rustc_back::PanicStrategy;
+use rustc_back::target::PanicStrategy;
 
 /// A list of dependencies for a certain crate type.
 ///