[interpreter] Fix debug stepping for generators.

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 044cf16f664946c1d525787522ce65372e530ff6..018640d806ffdbdaa9d0a0340f91f0b6cf18c738 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -214,7 +214,6 @@ class BytecodeGenerator::ControlScopeForTopLevel final
       case CMD_CONTINUE:
         UNREACHABLE();
       case CMD_RETURN:
-        generator()->builder()->SetReturnPosition();
         generator()->builder()->Return();
         return true;
       case CMD_RETHROW:
@@ -2289,6 +2288,7 @@ void BytecodeGenerator::VisitYield(Yield* expr) {
     }
 
     builder()->Bind(&resume_with_throw);
+    builder()->SetExpressionPosition(expr);
     builder()->LoadAccumulatorWithRegister(input).Throw();
 
     builder()->Bind(&resume_with_next);