[bug] potential segfault after changing composite type definition

[BenConnault]

Context at julia-user, including files to reproduce.

To reproduce, run:

include("segf.jl")
tt=DDCM.segf();
tt.tpi[1][1,1] 

With include("old_types.jl") in segf.jl, this returns 0.0.

With include("new_types.jl") in segf.jl, it throws sometimes a segfault, sometimes:

ERROR: no method getindex(SYSTEM: show(lasterr) caused an error
ERROR: no method Enumerate{I}(
 in showerror at repl.jl:111
 in showerror at repl.jl:66
 in anonymous at client.jl:93
 in with_output_color at util.jl:444
 in display_error at client.jl:91SYSTEM: show(lasterr) caused an error
WARNING: it is likely that something important is broken, and Julia will not be able to continue normally

[timholy]

This should have been fixed by the new framework for saving composite objects.