[IDE] Add doc comments for SignatureHelpResponse

Author: a7medev

tools/SourceKit/include/SourceKit/Core/LangSupport.h

@@ -1014,22 +1014,39 @@ class ConformingMethodListConsumer {
 
 struct SignatureHelpResponse {
   struct Parameter {
+    /// The offset of the parameter text in the signature text.
     unsigned Offset;
+
+    /// The length of the parameter text in the signature text.
     unsigned Length;
+
+    /// The documentation comment for the parameter.
     StringRef DocComment;
+
+    /// The internal parameter name.
     StringRef Name;
 
     Parameter() {}
   };
 
   struct Signature {
+    /// The text describing the signature.
     StringRef Text;
+
+    /// The documentation comment for the signature.
     StringRef Doc;
+
+    /// The index of the active parameter if any.
     std::optional<unsigned> ActiveParam;
+
+    /// The parameters for the signature.
     ArrayRef<Parameter> Params;
   };
 
+  /// The index of the active signature.
   unsigned ActiveSignature;
+
+  /// The available signatures/overloads.
   ArrayRef<Signature> Signatures;
 };