Remove qualify_declval clang-tidy check

Author: ldionne

libcxx/docs/CodingGuidelines.rst

@@ -36,7 +36,7 @@ Function overloading also applies to operators. Using ``&user_object`` may call
       ...
     }
 
-This is mostly enforced by the clang-tidy checks ``libcpp-robust-against-adl`` and ``libcpp-qualify-declval``.
+This is mostly enforced by the clang-tidy check ``libcpp-robust-against-adl``.
 
 Avoid including public headers
 ==============================

libcxx/test/tools/clang_tidy_checks/CMakeLists.txt

@@ -94,7 +94,6 @@ set(SOURCES
     internal_ftm_use.cpp
     nodebug_on_aliases.cpp
     proper_version_checks.cpp
-    qualify_declval.cpp
     robust_against_adl.cpp
     uglify_attributes.cpp
 

libcxx/test/tools/clang_tidy_checks/libcpp_module.cpp

@@ -15,7 +15,6 @@
 #include "internal_ftm_use.hpp"
 #include "nodebug_on_aliases.hpp"
 #include "proper_version_checks.hpp"
-#include "qualify_declval.hpp"
 #include "robust_against_adl.hpp"
 #include "uglify_attributes.hpp"
 
@@ -31,7 +30,6 @@ class LibcxxTestModule : public clang::tidy::ClangTidyModule {
     check_factories.registerCheck<libcpp::proper_version_checks>("libcpp-cpp-version-check");
     check_factories.registerCheck<libcpp::robust_against_adl_check>("libcpp-robust-against-adl");
     check_factories.registerCheck<libcpp::uglify_attributes>("libcpp-uglify-attributes");
-    check_factories.registerCheck<libcpp::qualify_declval>("libcpp-qualify-declval");
   }
 };
 } // namespace