[DFAJumpThreading] Handle select unfolding when user phi is not a dir… (#109511)

…ect successor

Previously the code assumed that the select instruction is defined in a
block that is a direct predecessor of the block where the PHINode uses
it. So, we were hitting an assertion when we tried to access the def
block as an incoming block for the user phi node.

This patch handles that case by using the correct end block and creating
a new phi node that aggregates both the values of the select in that end
block, and then using that new unfolded phi to overwrite the original
user phi node.

Fixes #106083

Change-Id: Ie471994cca232318f74a6e6438efa21e561c2dc0

0 files changed, 0 insertions, 0 deletions