[clangd] Fix diagnostic errors in the test code, NFC.

Reviewers: ilya-biryukov

Reviewed By: ilya-biryukov

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

Differential Revision: https://reviews.llvm.org/D44294

llvm-svn: 327293

clang-tools-extra/unittests/clangd/XRefsTests.cpp

@@ -596,7 +596,9 @@ TEST(GoToInclude, All) {
   auto FooH = testPath("foo.h");
   auto FooHUri = URIForFile{FooH};
 
-  const char *HeaderContents = R"cpp([[]]int a;)cpp";
+  const char *HeaderContents = R"cpp([[]]#pragma once
+                                     int a;
+                                     )cpp";
   Annotations HeaderAnnotations(HeaderContents);
   FS.Files[FooH] = HeaderAnnotations.code();