Increase the chance of printing a useful error when bootstrapping fails

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 93005e3164bf735039cef29bcf78dba28c1f6357..1573629b917793ba9b6c7b66b09803480dc1fb17 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -937,6 +937,9 @@ void ReportBootstrappingException(Handle<Object> exception,
         "Extension or internal compilation error in %s at line %d.\n",
         String::cast(location->script()->name())->ToCString().get(),
         line_number);
+  } else if (exception->IsString()) {
+    base::OS::PrintError("Extension or internal compilation error: %s.\n",
+                         String::cast(*exception)->ToCString().get());
   } else {
     base::OS::PrintError("Extension or internal compilation error.\n");
   }