V4: fix life range for phi node target that is never used.
V4: fix life range for phi node target that is never used.

When a temp is defined by a phi-node, but never used, still insert the
(very short) life range.

Change-Id: Ia976f496736a1606108fab7597c5d90048d9d55a
Reviewed-by: Lars Knoll <a812617a4072dcbeb80684eca0f369f0083af109@digia.com>

qmlc/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d