V4 regalloc: do not overwrite register availability in hole.

When a fixed interval for a register is inactive, the register is free
until that interval becomes active, or (and this was missing), until
another interval uses it before that position. So instead of blindly
overwriting the freeUntilPos, take the qMin of the existing one with
the intersection position.

Change-Id: I2730a748ef1e46b4782fbb9814e800eca52172f0
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
V4 regalloc: fix off-by-one in availability calculation.

Simplified the algorithm, and use it to iterate over all registers. The
previous version did not initialize bestReg correctly, thereby skipping
the first register (which could also be the best one).

Change-Id: I7e33f93a27e8fe64cd00acac755cf67ca5f0b1b8
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
qmltest: Register test object as a singleton

Change-Id: I5f6c404ff2901082f22b953b29aed08d3488f31d
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Alan Alpert <aalpert@blackberry.com>
qmltest: Add QTestDefinedVariables

QTestDefinedVariables is used by the QTestRootObject to check
is a preprocessor variable is defined.

Adding QT_OPENGL_ES_2_ANGLE. It can be useful to know
if it is defined (Win32 + Angle) while running a test.

Change-Id: I2f9ffb1028c94095c711ab64737b53b60c055312
Reviewed-by: Alan Alpert <aalpert@blackberry.com>