Cyclic dependency between vtkm_compiler_flags and vtkm_developer_flags

Consider the inter-dependency between the two targets established by target_link_libraries calls copied below:

• VTKmCompilerFlags.cmake:57-58

add_library(vtkm_compiler_flags INTERFACE)
...
target_link_libraries(vtkm_compiler_flags
    INTERFACE $<BUILD_INTERFACE:vtkm_developer_flags>)

• VTKmCompilerFlags.cmake:89-90

add_library(vtkm_developer_flags INTERFACE)
target_link_libraries(vtkm_developer_flags INTERFACE vtkm_compiler_flags)

@robertmaynard confirmed that is a bug and the intention is for vtkm_developer_flags to be consumed by vtkm_compiler_flags.