[clang-tools-extra] [clangd] Add a unit test suite for HeuristicResolver (PR #121313)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

In the latest update, matchers for the `DependentNameType` cases are revised to be more specific. Here, the approach I took was to match the context in which the types appear.

@hokein I believe your comment about using more specific matchers should be fully addressed now :)

https://github.com/llvm/llvm-project/pull/121313