[clang] [clang-tools-extra] [clang] Don't add documentation comments to the AST if not requested (PR #206363)

[Corentin Jabot via cfe-commits]

================
@@ -167,7 +167,7 @@ class IndexAction : public ASTFrontendAction {
   bool BeginInvocation(CompilerInstance &CI) override {
     // We want all comments, not just the doxygen ones.
     CI.getLangOpts().CommentOpts.ParseAllComments = true;
-    CI.getLangOpts().RetainCommentsFromSystemHeaders = true;
+    CI.getLangOpts().CommentOpts.RetainCommentsFromSystemHeaders = true;
----------------
cor3ntin wrote:

we probably want 
CI.getLangOpts().CommentOpts.RetainComments = true;

https://github.com/llvm/llvm-project/pull/206363