V4 IR: change datastructures for dominator calculations.
V4 IR: change datastructures for dominator calculations.

Replace hashes from basic-block to basic-block with vectors that
associate basic-block index to basic-block index.

Change-Id: I834ea3d825e4d2b02c075b1b0f080f5a65f41317
Reviewed-by: Fawzi Mohamed <7388270c57edd0fabd71d8eb0322d66e3c40e57e@digia.com>

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