Use associative type defaults in {Layout,FnAbi}OfHelpers.

This avoids some repetitive boilerplate code.

Author: nnethercote

src/common.rs

@@ -309,17 +309,13 @@ pub(crate) struct FunctionCx<'m, 'clif, 'tcx: 'm> {
 }
 
 impl<'tcx>LayoutOfHelpers<'tcx>forFunctionCx<'_,'_,'tcx>{
-typeLayoutOfResult = TyAndLayout<'tcx>;
-
 #[inline]
 fnhandle_layout_err(&self,err:LayoutError<'tcx>,span:Span,ty:Ty<'tcx>) -> ! {
 RevealAllLayoutCx(self.tcx).handle_layout_err(err, span, ty)
 }
 }
 
 impl<'tcx>FnAbiOfHelpers<'tcx>forFunctionCx<'_,'_,'tcx>{
-typeFnAbiOfResult = &'tcxFnAbi<'tcx,Ty<'tcx>>;
-
 #[inline]
 fnhandle_fn_abi_err(
 &self,
@@ -450,8 +446,6 @@ impl<'tcx> FunctionCx<'_, '_, 'tcx> {
 pub(crate)structRevealAllLayoutCx<'tcx>(pub(crate)TyCtxt<'tcx>);
 
 impl<'tcx>LayoutOfHelpers<'tcx>forRevealAllLayoutCx<'tcx>{
-typeLayoutOfResult = TyAndLayout<'tcx>;
-
 #[inline]
 fnhandle_layout_err(&self,err:LayoutError<'tcx>,span:Span,ty:Ty<'tcx>) -> ! {
 ifletLayoutError::SizeOverflow(_) | LayoutError::ReferencesError(_) = err {
@@ -466,8 +460,6 @@ impl<'tcx> LayoutOfHelpers<'tcx> for RevealAllLayoutCx<'tcx> {
 }
 
 impl<'tcx>FnAbiOfHelpers<'tcx>forRevealAllLayoutCx<'tcx>{
-typeFnAbiOfResult = &'tcxFnAbi<'tcx,Ty<'tcx>>;
-
 #[inline]
 fnhandle_fn_abi_err(
 &self,