RFR(S): 8203215: IdealLoopTree::split_outer_loop leaves phi-nodes with only one input

[Roland Westrelin]

Hi Nils,

> Webrev: http://cr.openjdk.java.net/~neliasso/8203215/webrev.01/

replace_input_of(n,..) calls rehash_node_delayed(n) so:
 1806       igvn.rehash_node_delayed(old_phi);

is redundant?

Also, it seems risky to me to perform an igvn with major_progress
cleared (as it can cause some premature clean up). So, maybe move:

 2645   C->clear_major_progress();

down after the igvn?

Roland.