Change POST_BUILD for h5watch-files to custom target and commands.

This keeps the command line from getting too long with the ninja generator.

hl/tools/h5watch/CMakeTests.cmake

@@ -56,19 +56,14 @@ set (H5WATCH_TEST_FILES
 
 # make test dir
 file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/testfiles")
-add_custom_target(h5watch-files ALL COMMENT "Copying files needed by h5watch tests")
 
 foreach (h5watch_file ${H5WATCH_TEST_FILES})
-  set (dest "${PROJECT_BINARY_DIR}/testfiles/${h5watch_file}")
-  #message (STATUS " Copying ${h5watch_file}")
-  add_custom_command (
-      TARGET     h5watch-files
-      POST_BUILD
-      COMMAND    ${CMAKE_COMMAND}
-      ARGS       -E copy_if_different ${HDF5_HL_TOOLS_DIR}/testfiles/${h5watch_file} ${dest}
-  )
+  HDFTEST_COPY_FILE("${HDF5_HL_TOOLS_DIR}/testfiles/${h5watch_file}" "${PROJECT_BINARY_DIR}/testfiles/${h5watch_file}" "h5watch-files_files")
 endforeach ()
 
+add_custom_target(h5watch-files_files ALL COMMENT "Copying files needed by h5watch-files tests" DEPENDS ${h5watch-files_files_list})
+
+
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