hg: jdk/sandbox: 8233820: Test crashed with assert(phi->operand_count() != 1 || phi->subst() != phi) failed: missed trivial simplification

[chris.hegarty at oracle.com]

Changeset: ad05ed6f2a77
Author:    mdoerr
Date:      2019-11-12 16:13 +0100
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/ad05ed6f2a77

8233820: Test crashed with assert(phi->operand_count() != 1 || phi->subst() != phi) failed: missed trivial simplification
Summary: Verification code needs to skip illegal phi functions.
Reviewed-by: thartmann, vlivanov

! src/hotspot/share/c1/c1_GraphBuilder.cpp
! src/hotspot/share/c1/c1_Optimizer.cpp