[libc++] Mark two <chrono> tests as unsupported on AppleClang 11

The operator""y and operator""d will eventually be supported by
AppleClang, but no released version supports them at the moment.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@368749 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/time/time.cal/time.cal.day/time.cal.day.nonmembers/literals.pass.cpp

@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-5, clang-6, clang-7
-// UNSUPPORTED: apple-clang-6, apple-clang-7, apple-clang-8, apple-clang-9, apple-clang-10
+// UNSUPPORTED: apple-clang-6, apple-clang-7, apple-clang-8, apple-clang-9, apple-clang-10, apple-clang-11
 
 // <chrono>
 // class day;

test/std/utilities/time/time.cal/time.cal.year/time.cal.year.nonmembers/literals.pass.cpp

@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-5, clang-6, clang-7
-// UNSUPPORTED: apple-clang-6, apple-clang-7, apple-clang-8, apple-clang-9, apple-clang-10
+// UNSUPPORTED: apple-clang-6, apple-clang-7, apple-clang-8, apple-clang-9, apple-clang-10, apple-clang-11
 
 // <chrono>
 // class year;