qv4isel_moth.cpp: Fix MSVC-warnings about operator unary minus applied to unsigned.
qv4isel_moth.cpp: Fix MSVC-warnings about operator unary minus applied to unsigned.

compiler\qv4isel_moth.cpp(1041) : warning C4146: unary minus operator applied to  unsigned type, result still unsigned
compiler\qv4isel_moth.cpp(1056) : warning C4146: unary minus operator applied to  unsigned type, result still unsigned
compiler\qv4isel_moth.cpp(1096) : warning C4146: unary minus operator applied to  unsigned type, result still unsigned

Change-Id: Idb4714a277486ff736f49c50c7e840fd62e2150f
Reviewed-by: Lars Knoll <a812617a4072dcbeb80684eca0f369f0083af109@digia.com>

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