Merge pull request #68193 from allevato/no-generic-char-traits

Replace generic `basic_string` overloads of `StableHasher::combine` with concrete ones.

Author: allevato

include/swift/Basic/StableHasher.h

@@ -173,7 +173,11 @@ class StableHasher final {
     return combine_many(arg.first, arg.second);
   }
 
-  template <typename T> void combine(const std::basic_string<T> &arg) {
+  void combine(const std::basic_string<char> &arg) {
+    return combine_range(arg.begin(), arg.end());
+  }
+
+  void combine(const std::basic_string<wchar_t> &arg) {
     return combine_range(arg.begin(), arg.end());
   }