[clang] [clang-tools-extra] [ASTMatchers][NFC] Replace `makeMatcher` function with CTAD (PR #147197)

[Nicolas van Kempen via cfe-commits]

================
@@ -672,12 +672,7 @@ class Matcher {
   DynTypedMatcher Implementation;
 };  // class Matcher
 
-/// A convenient helper for creating a Matcher<T> without specifying
-/// the template type argument.
-template <typename T>
-inline Matcher<T> makeMatcher(MatcherInterface<T> *Implementation) {
-  return Matcher<T>(Implementation);
-}
+template <typename T> Matcher(MatcherInterface<T> *) -> Matcher<T>;
----------------
nicovank wrote:

Maybe just a comment here indicating this is a user-defined deduction guide.

https://github.com/llvm/llvm-project/pull/147197