Remove <experimental/coroutine> from the module map for now. It doesn't work unless modules are enabled

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@303838 91177308-0d34-0410-b5e6-96231b3b80d8

include/module.modulemap

@@ -501,10 +501,12 @@ module std [system] {
       header "experimental/chrono"
       export *
     }
-    module coroutine {
-      header "experimental/coroutine"
-      export *
-    }
+    // FIXME: This module only works when -fcoroutines-ts is enabled and it
+    // breaks the modules build otherwise.
+    // module coroutine {
+    //  header "experimental/coroutine"
+    //  export *
+    // }
     module deque {
       header "experimental/deque"
       export *