[dexp] Dump JSON representations of fuzzy find requests

[kbobyrev]

Summary

This might be useful when building requests database for benchmarks and tests.

[ioeric]

clang-tools-extra/clangd/index/dex/dexp/Dexp.cpp

126

Any reason not to print this always?

[kbobyrev]

I thought that we might not want to produce too much information, but I don't have anything against printing the JSON representation of every user request.

clang-tools-extra/clangd/index/dex/dexp/Dexp.cpp

void run() override {
     FuzzyFindRequest Request;
     Request.Limit = Limit;
     Request.Query = Query;
     if (Scopes.getNumOccurrences() > 0) {
       llvm::SmallVector<StringRef, 8> Scopes;
       StringRef(this->Scopes).split(Scopes, ',');
       Request.Scopes = {Scopes.begin(), Scopes.end()};
     }
+    llvm::outs() << llvm::formatv("Request:\n{0}\n\n", toJSON(Request));
     // FIXME(kbobyrev): Print symbol final scores to see the distribution.
     static const auto OutputFormat = "{0,-4} | {1,-40} | {2,-25}\n";
     llvm::outs() << llvm::formatv(OutputFormat, "Rank", "Symbol ID",
                                   "Symbol Name");
     size_t Rank = 0;
     Index->fuzzyFind(Request, [&](const Symbol &Sym) {
       llvm::outs() << llvm::formatv(OutputFormat, Rank++, Sym.ID.str(),
                                     Sym.Name);