[clangd] Add ':' to completion trigger characters.

[ilya-biryukov]

Summary

Without it we don't get completion requests from VSCode after
nested name qualifiers (e.g. after 'std::').

[krasimir]

Looks good!

clang-tools-extra/trunk/clangd/ClangdLSPServer.cpp

void ClangdLSPServer::LSPProtocolCallbacks::onInitialize(StringRef ID,
   Out.writeMessage(
       R"({"jsonrpc":"2.0","id":)" + ID +
       R"(,"result":{"capabilities":{
           "textDocumentSync": 1,
           "documentFormattingProvider": true,
           "documentRangeFormattingProvider": true,
           "documentOnTypeFormattingProvider": {"firstTriggerCharacter":"}","moreTriggerCharacter":[]},
           "codeActionProvider": true,
-          "completionProvider": {"resolveProvider": false, "triggerCharacters": [".",">"]},
+          "completionProvider": {"resolveProvider": false, "triggerCharacters": [".",">",":"]},
           "definitionProvider": true
         }}})");
 }
 
 void ClangdLSPServer::LSPProtocolCallbacks::onShutdown(JSONOutput &Out) {
   LangServer.IsDone = true;
 }
 

clang-tools-extra/trunk/test/clangd/formatting.test

 # RUN: clangd < %s | FileCheck %s
 # It is absolutely vital that this file has CRLF line endings.
 #
 Content-Length: 125
 
 {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
-# CHECK: Content-Length: 462
+# CHECK: Content-Length: 466
 # CHECK: {"jsonrpc":"2.0","id":0,"result":{"capabilities":{
 # CHECK:   "textDocumentSync": 1,
 # CHECK:   "documentFormattingProvider": true,
 # CHECK:   "documentRangeFormattingProvider": true,
 # CHECK:   "documentOnTypeFormattingProvider": {"firstTriggerCharacter":"}","moreTriggerCharacter":[]},
 # CHECK:   "codeActionProvider": true,
-# CHECK:   "completionProvider": {"resolveProvider": false, "triggerCharacters": [".",">"]},
+# CHECK:   "completionProvider": {"resolveProvider": false, "triggerCharacters": [".",">",":"]},
 # CHECK:   "definitionProvider": true
 # CHECK: }}}
 #
 Content-Length: 193
 
 {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///foo.c","languageId":"c","version":1,"text":"int foo ( int x ) {\n    x = x+1;\n    return x;\n    }"}}}
 #
 #