[clang-tools-extra] [clangd] Augment code completion results with documentation from the index. (PR #120099)

[Nathan Ridge via cfe-commits]

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@@ -1101,6 +1101,42 @@ int x = foo^
       Contains(AllOf(named("foo"), doc("This comment should be retained!"))));
 }
 
+TEST(CompletionTest, CommentsOnMembers) {
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HighCommander4 wrote:

nit: call this `CommentsOnMembersFromHeader`

https://github.com/llvm/llvm-project/pull/120099