subsumespec_app1, subsumespec_app2

[andrew-appel]

In floyd/forward.v, the lemmas subsumespec_app1 and subsumespec_app1 take forever. Same for tycontext_sub_Gprog_app1, tycontext_sub_Gprog_app2.

Perhaps with explicitly instantiated arguments to funspec_sub_si_refl, these lemmas would be instantaneous.

[andrew-appel]

Solution: apply seplog.funspec_sub_si_refl instead of apply funspec_sub_si_refl. I've fixed this in a branch that may or may not make into master someday, but this fix can also be applied independently at any time.