[clangd] Handle go-to-definition in macro invocations where the target appears...

[clangd] Handle go-to-definition in macro invocations where the target appears in the expansion multiple times

Fixes https://github.com/clangd/clangd/issues/234

Reviewers: sammccall

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72041