Slow Precise Code-Intel Tooltips in C/C++ Code

Created by: tistru

Reporting Customer: https://app.hubspot.com/contacts/2762526/contact/25700601

• Sourcegraph version: 3.19

Steps to reproduce:

1. Find a public repo that has c/cpp code and has lsif uploaded. For example: https://sourcegraph.com/github.com/protocolbuffers/protobuf@f5bdd7cd56aa86612e166706ed8ef139db06edf2/-/tree/src/google/protobuf/compiler/cpp
2. Open a .cc/.cpp/.hpp file and hover over several identifiers. Observe that the time it takes to populate the code-intel tooltip ranges from instant to >10s

Expected behavior:

TIme to load the tooltips should be near instant (within a few seconds)

Actual behavior:

See sporadic cases where the time to load the tooltip can take upwards of 60s. In the worst case, it never loads at all and the spinning icon remains with an eventual gateway timeout HTTP error in the browser dev tools.