[lldb/Utility] Fix StructuredData::ParseJSONValue for null items

This patch fixes the JSON parser for StructuredData to handle JSON null
entries.

Differential Revision: https://reviews.llvm.org/D135616

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>

lldb/source/Utility/StructuredData.cpp

@@ -69,6 +69,9 @@ static StructuredData::ObjectSP ParseJSONValue(json::Value &value) {
   if (auto d = value.getAsNumber())
     return std::make_shared<StructuredData::Float>(*d);
 
+  if (auto n = value.getAsNull())
+    return std::make_shared<StructuredData::Null>();
+
   return StructuredData::ObjectSP();
 }