This fixes a possible issue when we could hoist an instruction up to a widenable
condition intrinsic call without making sure its operands are available at
hoisiting point.
Recently insertion point finding algorithm changed a bit, so this availability
check became necessary.
Verifier would crash after we handled the following special case:
L >u C0 && L >u C1 -> L >u max(C0, C1),
Previously we would insert the new condition right before the widenable condition
branch where all L operands were available.
Now we may choose the widenable condition intrinsic call as insertion point and it may
happen so that the L operands are computed after the call, so we have to make sure that
L operands are available at the point we want to insert it.
Differential Revision: https://reviews.llvm.org/D144944
4e34915b6d