Add support for rule hints

A rule hint is a target attribute, for example:

[rule_hint=cxx] exe{hello}: c{hello}

Rule hints can be used to resolve ambiguity when multiple rules match the same
target as well as to override an unambiguous match.

1 files changed, 1 insertions, 1 deletions

diff --git a/libbuild2/test/target.cxx b/libbuild2/test/target.cxx
index ce88baa..852abdf 100644
--- a/libbuild2/test/target.cxx
+++ b/libbuild2/test/target.cxx
@@ -56,7 +56,7 @@ namespace build2
       &testscript_target_pattern,
       nullptr,
       &file_search,
-      false
+      target_type::flag::none
     };
   }
 }