[clang] Add code completion for #embed directive in C23 mode

Author: quanzhuo

clang/lib/Sema/SemaCodeComplete.cpp

@@ -10208,6 +10208,24 @@ void SemaCodeCompletion::CodeCompletePreprocessorDirective(bool InConditional) {
   Builder.AddPlaceholderChunk("message");
   Results.AddResult(Builder.TakeString());
 
+  if (getLangOpts().C23) {
+    // #embed "header"
+    Builder.AddTypedTextChunk("embed");
+    Builder.AddChunk(CodeCompletionString::CK_HorizontalSpace);
+    Builder.AddTextChunk("\"");
+    Builder.AddPlaceholderChunk("header");
+    Builder.AddTextChunk("\"");
+    Results.AddResult(Builder.TakeString());
+
+    // #embed <header>
+    Builder.AddTypedTextChunk("embed");
+    Builder.AddChunk(CodeCompletionString::CK_HorizontalSpace);
+    Builder.AddTextChunk("<");
+    Builder.AddPlaceholderChunk("header");
+    Builder.AddTextChunk(">");
+    Results.AddResult(Builder.TakeString());
+  }
+
   // Note: #ident and #sccs are such crazy anachronisms that we don't provide
   // completions for them. And __include_macros is a Clang-internal extension
   // that we don't want to encourage anyone to use.