Replace absolute paths with relative ones

Modern compilers allow reaching external crates
like std or core via relative paths in modules
outside of lib.rs and main.rs.

compiler/rustc_codegen_ssa/src/traits/mod.rs

@@ -85,7 +85,7 @@ impl<'tcx, T> CodegenMethods<'tcx> for T where
 }
 
 pub trait HasCodegen<'tcx>:
-    Backend<'tcx> + ::std::ops::Deref<Target = <Self as HasCodegen<'tcx>>::CodegenCx>
+    Backend<'tcx> + std::ops::Deref<Target = <Self as HasCodegen<'tcx>>::CodegenCx>
 {
     type CodegenCx: CodegenMethods<'tcx>
         + BackendTypes<