Remove redundant outlives declarations

Author: spastorino

src/librustc_mir/borrow_check/nll/type_check/mod.rs

@@ -202,7 +202,7 @@ enum FieldAccessError {
 /// The sanitize_XYZ methods here take an MIR object and compute its
 /// type, calling `span_mirbug` and returning an error type if there
 /// is a problem.
-struct TypeVerifier<'a, 'b: 'a, 'gcx: 'b + 'tcx, 'tcx: 'b> {
+struct TypeVerifier<'a, 'b: 'a, 'gcx: 'tcx, 'tcx: 'b> {
     cx: &'a mut TypeChecker<'b, 'gcx, 'tcx>,
     mir: &'a Mir<'tcx>,
     last_span: Span,
@@ -611,7 +611,7 @@ impl<'a, 'b, 'gcx, 'tcx> TypeVerifier<'a, 'b, 'gcx, 'tcx> {
 /// constraints needed for it to be valid and well-typed. Along the
 /// way, it accrues region constraints -- these can later be used by
 /// NLL region checking.
-struct TypeChecker<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
+struct TypeChecker<'a, 'gcx: 'tcx, 'tcx: 'a> {
     infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
     param_env: ty::ParamEnv<'gcx>,
     last_span: Span,