[ODE] dNormalize3 speedup

[Oles V. Shishkovtsov]

Hello,

Can somebody who has access to CVS add following snipped to
"odemath.cpp", line 37 (the start of the function).

This is a faster sequence for normalizing vectors which has "normal"
magnitude, not the extremely small one. The old behaviour remains the
same for problematic cases.

According to our profile this small function is in top-20, during
stress-testing. Adding following removes it from profile completely.

--------------------------------------------------------------------
        dReal   sqr_magnitude   = a[0]*a[0] + a[1]*a[1] + a[2]*a[2];
        dReal   epsilon         = 1.192092896e-05F;
        if      (sqr_magnitude > epsilon)
        {
                dReal   l       =       dRecipSqrt(sqr_magnitude);
                a[0]            *=      l;
                a[1]            *=      l;
                a[2]            *=      l;
                return;
        }
--------------------------------------------------------------------

-- 
Best regards,
 Oles V. Shishkovtsov
 GSC-Game World
 oles at gsc-game.kiev.ua