Remove BackendTypes constraint from traits that don't need it.

Author: nnethercote

compiler/rustc_codegen_ssa/src/traits/coverageinfo.rs

@@ -1,9 +1,7 @@
 use rustc_middle::mir::coverage::CoverageKind;
 use rustc_middle::ty::Instance;
 
-use super::BackendTypes;
-
-pub trait CoverageInfoBuilderMethods<'tcx>: BackendTypes {
+pub trait CoverageInfoBuilderMethods<'tcx> {
     /// Performs any start-of-function codegen needed for coverage instrumentation.
     ///
     /// Can be a no-op in backends that don't support coverage instrumentation.

compiler/rustc_codegen_ssa/src/traits/declare.rs

@@ -2,9 +2,7 @@ use rustc_hir::def_id::DefId;
 use rustc_middle::mir::mono::{Linkage, Visibility};
 use rustc_middle::ty::Instance;
 
-use super::BackendTypes;
-
-pub trait PreDefineMethods<'tcx>: BackendTypes {
+pub trait PreDefineMethods<'tcx> {
     fn predefine_static(
         &self,
         def_id: DefId,