gccrs: ast: Dump inferred type

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ast/rust-ast-dump.cc

@@ -1661,6 +1661,9 @@ Dump::visit (SliceType &type)
 void
 Dump::visit (InferredType &)
 {
+  // Syntax:
+  //    _
+
   stream << "_";
 }