Enhance GN introspection

tools/gn/label_pattern.cc

Index: tools/gn/label_pattern.cc
diff --git a/tools/gn/label_pattern.cc b/tools/gn/label_pattern.cc
index 4b31174d946dfb2f64f8834f31e00b2b1dc3e1b5..712826fe562e0c042df803bbe90d5237dba6d0fc 100644
--- a/tools/gn/label_pattern.cc
+++ b/tools/gn/label_pattern.cc
@@ -216,6 +216,12 @@ LabelPattern LabelPattern::GetPattern(const SourceDir& current_dir,
   return LabelPattern(type, dir, base::StringPiece(), toolchain_label);
 }
 
+bool LabelPattern::HasWildcard(const std::string& str) {
+  // Just look for a star. In the future, we may want to handle escaping or
+  // other types of patterns.
+  return str.find('*') != std::string::npos;
+}
+
 bool LabelPattern::Matches(const Label& label) const {
   if (!toolchain_.is_null()) {
     // Toolchain must match exactly.