Compile fix for MSVC2013

This fixes an inclusion error caused by eb8a091 under WinRT x64 MSVC2013.

Change-Id: I3ebae0788264f4e3ccc0ae9f2bb4dbc4cceaa155
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Reviewed-by: Ulf Hermann <ulf.hermann@digia.com>
V4 IR: changed worklist used while doing optimizations.

Change the worklist in the optimizeSSA function to allow only one entry
for a statement. This prevents re-processing a statement multiple times,
and could lead to crashes when the statement was removed in an earlier
pass.

Change-Id: I2f09cf74525cfe19708ec7a8bc6d555218625e87
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
V4 IR: remove unused phi targets.

Remove all phi nodes whose target temps have no uses. This obvious
optimization was missing.

Change-Id: I24354e225ba7b01a3c2a6f4b2e40dd78d6ee3d7d
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
V4: Do not reverse-propagate int32 conversion through unary minus.

Conversion to int32 might truncate, and because int32 is two's
complement, INT_MIN might get converted incorrectly.

Change-Id: Iaf893d3bd619f4c5791654e609f96cffca5c6917
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>