test: Add forward decls to repro grammar + test case

cmd/scip/tests/reprolang/bindings/go/repro/ast.go

@@ -27,7 +27,8 @@ func (r *relationships) identifiers() []*identifier {
 }
 
 type referenceStatement struct {
-	name *identifier
+	name          *identifier
+	isForwardDecl bool
 }
 
 type identifier struct {

cmd/scip/tests/reprolang/bindings/go/repro/parser.go

@@ -62,7 +62,8 @@ func (s *reproSourceFile) loadStatements() {
 			}
 		case "reference_statement":
 			s.references = append(s.references, &referenceStatement{
-				name: newIdentifier(s, child.ChildByFieldName("name")),
+				name:          newIdentifier(s, child.ChildByFieldName("name")),
+				isForwardDecl: child.ChildByFieldName("forward_decl") != nil,
 			})
 		}
 	}

cmd/scip/tests/reprolang/bindings/go/repro/scip.go

@@ -63,7 +63,11 @@ func (s *reproSourceFile) occurrences() []*scip.Occurrence {
 		emit(rel.relations)
 	}
 	for _, ref := range s.references {
-		result = append(result, ref.name.occurrence(scip.SymbolRole_UnspecifiedSymbolRole))
+		role := scip.SymbolRole_UnspecifiedSymbolRole
+		if ref.isForwardDecl {
+			role = scip.SymbolRole_ForwardDeclaration
+		}
+		result = append(result, ref.name.occurrence(role))
 	}
 	return result
 }

cmd/scip/tests/reprolang/grammar.js

@@ -22,7 +22,12 @@ module.exports = grammar({
         field('name', $.identifier),
         field('roles', repeat($._definition_relations))
       ),
-    reference_statement: $ => seq('reference', field('name', $.identifier)),
+    reference_statement: $ =>
+      seq(
+        'reference',
+        field('forward_decl', optional('forward_decl')),
+        field('name', $.identifier)
+      ),
     _definition_relations: $ =>
       choice(
         $.implementation_relation,