[debugger] Ensure at least one breakable position per function.

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 1cb7ba850192c714d7ec45b3e6f6f1caa93a7a00..c4026b59ec1659c024f231fca7d6a561b6c39a72 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -620,7 +620,9 @@ void BytecodeGenerator::MakeBytecodeBody() {
 
   // Visit illegal re-declaration and bail out if it exists.
   if (scope()->HasIllegalRedeclaration()) {
-    VisitForEffect(scope()->GetIllegalRedeclaration());
+    Expression* illegal = scope()->GetIllegalRedeclaration();
+    builder()->SetExpressionAsStatementPosition(illegal);
+    VisitForEffect(illegal);
     return;
   }