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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def msvc_set_PCHPDBFLAGS(env):
 """ Set appropriate PCHPDBFLAGS for the MSVC version being used. """

    if env.get('MSVC_VERSION',False):
        maj, min = msvc_version_to_maj_min(env['MSVC_VERSION'])
        if maj < 8:
            env['PCHPDBFLAGS'] = SCons.Util.CLVar(['${(PDB and "/Yd") or ""}'])
        else:
            env['PCHPDBFLAGS'] = ''
    else:
        # Default if we can't determine which version of MSVC we're using
        env['PCHPDBFLAGS'] = SCons.Util.CLVar(['${(PDB and "/Yd") or ""}'])