Remove path_span argument to the visit_path_segment methods.

The `visit_path_segment` method of both the AST and HIR visitors has a
`path_span` argument that isn't necessary. This commit removes it.

There are two very small and inconsequential functional changes.

- One call to `NodeCollector::insert` now is passed a path segment
  identifier span instead of a full path span. This span is only used in
a panic message printed in the case of an internal compiler bug.

- Likewise, one call to `LifetimeCollectVisitor::record_elided_anchor`
  now uses a path segment identifier span instead of a full path span.
  This span is used to make some `'_` lifetimes.

compiler/rustc_lint/src/builtin.rs

@@ -1467,7 +1467,7 @@ impl TypeAliasBounds {
                 if TypeAliasBounds::is_type_variable_assoc(qpath) {
                     self.err.span_help(span, fluent::lint::builtin_type_alias_bounds_help);
                 }
-                intravisit::walk_qpath(self, qpath, id, span)
+                intravisit::walk_qpath(self, qpath, id)
             }
         }
 

compiler/rustc_lint/src/early.rs

@@ -266,9 +266,9 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
         ast_visit::walk_path(self, p);
     }
 
-    fn visit_path_segment(&mut self, path_span: Span, s: &'a ast::PathSegment) {
+    fn visit_path_segment(&mut self, s: &'a ast::PathSegment) {
         self.check_id(s.id);
-        ast_visit::walk_path_segment(self, path_span, s);
+        ast_visit::walk_path_segment(self, s);
     }
 
     fn visit_attribute(&mut self, attr: &'a ast::Attribute) {