[compiler-rt] Disable building LibFuzzer for WatchOS and the corresponding simulator.

rdar://problem/59466685

Author: delcypher

compiler-rt/cmake/config-ix.cmake

@@ -500,6 +500,10 @@ if(APPLE)
     endforeach()
   endif()
 
+  # Explictly disable unsupported Sanitizer configurations.
+  list(REMOVE_ITEM FUZZER_SUPPORTED_OS "watchos")
+  list(REMOVE_ITEM FUZZER_SUPPORTED_OS "watchossim")
+
   # for list_intersect
   include(CompilerRTUtils)