RFR(S) 8016157: During CTW: C2: assert(!def_outside->member(r)) failed: Use of external LRG overlaps the same LRG defined in this block

[Niclas Adlertz]

Hi all, 

In bug 8005956 (https://jbs.oracle.com/bugs/browse/JDK-8005956) this assert triggered when trying to rematerialize reaches at phi nodes. This time it's failing because of rematerialization at uses (reg_split.cpp: 931).  These are the only two places that rematerialization is handled during splitting.

Doing the same fix as for JDK-8005956, i.e. removing rematerialization for nodes with live range input, gave too much performance regression. Instead, this fix invalidates rematerialization of the node type that is causing the problem negD node.

WEBREV: http://cr.openjdk.java.net/~adlertz/JDK-8016157/webrev00/
JBS: https://jbs.oracle.com/bugs/browse/JDK-8016157

Kind Regards,
Niclas Adlertz