Replace constant conditional branches by unconditional branches

BUG=
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1847423003 .
diff --git a/src/IceCfg.cpp b/src/IceCfg.cpp
index 2d16734..79dfd76 100644
--- a/src/IceCfg.cpp
+++ b/src/IceCfg.cpp
@@ -283,7 +283,7 @@
 
   TimerMarker T(TimerStack::TT_phiValidation, this);
   for (CfgNode *Node : Nodes)
-    Node->validatePhis();
+    Node->enforcePhiConsistency();
 }
 
 void Cfg::renumberInstructions() {