Silence warnings on unqualified calls to std::move

This is a new compiler warning add to at least Apple Clang. For now
we're choosing to silence the warning until at least other compilers
come to an agreement on whether this should be a warning.

CMakeLists.txt

@@ -225,6 +225,12 @@ else()
   if (NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-literal-suffix>)
   endif()
+
+  # Disable newer Apple Clang warnings about unqualified calls to std::move
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+    add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-unqualified-std-cast-call>)
+  endif()
+
 endif()
 
 # Definitions for all targets