[clangd] Fix Go to Definition not working in VSCode extension

[malaperle]

Summary

The URI conversion logic was returning 'undefined' when going from server to
VSCode which broke the Go to Definition functionality.

[krasimir]

Looks good! This is better than my https://reviews.llvm.org/D35238!

[malaperle]

In the other review: "The tool is fine with spaces encoded as %20 by the way." If that's true, wouldn't that mean the other review is the way to go?

clangd/clients/clangd-vscode/src/extension.ts

export function activate(context: vscode.ExtensionContext) {
     const clientOptions: vscodelc.LanguageClientOptions = {
         // Register the server for C/C++ files
         documentSelector: ['c', 'cc', 'cpp', 'h', 'hh', 'hpp'],
         uriConverters: {
             // FIXME: by default the URI sent over the protocol will be percent encoded (see rfc3986#section-2.1)
             //        the "workaround" below disables temporarily the encoding until decoding
             //        is implemented properly in clangd
             code2Protocol: (uri: vscode.Uri) : string => uri.toString(true),
-            protocol2Code: (uri: string) : vscode.Uri => undefined
+            protocol2Code: (uri: string) : vscode.Uri => vscode.Uri.parse(uri)
         }
     };
 
     const clangdClient = new vscodelc.LanguageClient('Clang Language Server', serverOptions, clientOptions);
 
     function applyTextEdits(uri: string, edits: vscodelc.TextEdit[]) {
         let textEditor = vscode.window.activeTextEditor;