[clangd] Fix irrelevant declaratations in goto definition (on macros).

Summary:
DeclrationAndMacrosFinder will find some declarations (not macro!) that are
referened inside the macro somehow, isSearchedLocation() is not sufficient, we
don't know whether the searched source location is macro or not.

Reviewers: ilya-biryukov

Subscribers: klimek, jkorous-apple, ioeric, cfe-commits

Differential Revision: https://reviews.llvm.org/D44293

llvm-svn: 327387