@begin: scope:[]  from
  [0] phi()
  to:@1
@1: scope:[]  from @begin
  [1] phi()
  [2] call main 
  to:@end
@end: scope:[]  from @1
  [3] phi()

(void()) main()
main: scope:[main]  from @1
  [4] phi()
  to:main::@1
main::@1: scope:[main]  from main main::@2
  [5] (bool) framedone#2 ← phi( main/true main::@2/false )
  to:main::@2
main::@2: scope:[main]  from main::@1 main::@2
  [6] if((bool) framedone#2) goto main::@1
  to:main::@2
