Make GT_LIST processing non-recursive to avoid StackOverflow.

Make GT_LIST processing non-recursive to avoid StackOverflow.

We had some internal cases where crossgen failed with StackOverflow exception
when compiling huge methods. In particular, the methods had GT_PHI nodes with
huge number of arguments.

StackOverflow was happening in multiple places. Recent LIR changes eliminated two of those places,
these changes eliminate two more: gtSetEvalOrder and fgDebugCheckFlags (debug only). We already had
gtSetListOrder but it was only used for call arg lists. I made gtSetListOrder non-recursive and also generalized
to handle other GT_LIST nodes.

With that with these changes the huge repros can now be crossgen'd.

I verified no assembly diffs in SuperPMI.

I'm verifying overall throughput effect.