Merge all of my changes from merge-back-to-feature-vfd_swmr-attempt-1,

including the merge of `hdffv/hdf5/develop`, back to the branch that Vailin and
I share.

Now I need to put this branch on a fork with a less confusing name than
vchoi_fork!

config/cmake_ext_mod/HDFUseCXX.cmake

@@ -48,8 +48,8 @@ macro (HDF_CXX_FUNCTION_TEST OTHER_TEST)
   if (NOT DEFINED ${OTHER_TEST})
     set (MACRO_CHECK_FUNCTION_DEFINITIONS "-D${OTHER_TEST} ${CMAKE_REQUIRED_FLAGS}")
     set (OTHER_TEST_ADD_LIBRARIES)
-    if (CMAKE_REQUIRED_LIBRARIES)
-      set (OTHER_TEST_ADD_LIBRARIES "-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
+    if (HDF5_REQUIRED_LIBRARIES)
+      set (OTHER_TEST_ADD_LIBRARIES "-DLINK_LIBRARIES:STRING=${HDF5_REQUIRED_LIBRARIES}")
     endif ()
 
     foreach (def
@@ -96,7 +96,7 @@ endmacro ()
 # Check a bunch of cxx functions
 #-----------------------------------------------------------------------------
 if (CMAKE_CXX_COMPILER_LOADED)
-  foreach (test
+  foreach (cxx_test
       OLD_HEADER_FILENAME
       HDF_NO_NAMESPACE
       HDF_NO_STD
@@ -104,6 +104,6 @@ if (CMAKE_CXX_COMPILER_LOADED)
       NO_STATIC_CAST
       CXX_HAVE_OFFSETOF
   )
-    HDF_CXX_FUNCTION_TEST (${test})
+    HDF_CXX_FUNCTION_TEST (${cxx_test})
   endforeach ()
 endif ()