swift234

[sil-combine] Make output of (extract (load)) -> (load (element_addr)) deterministic by not using pointer address as a sorting criteria for vardecls.

Instead for vardecls, we use the index of the field in the structdecl itself as
a stable ordering of vardecls.

I validated that the indeterminism was gone by running the failing test 1000
times in a row. Doug and I were hitting the indeterminism with well less than
100 iterations before, so I feel the number of iterations is sufficient.

Swift SVN r13859