Bug#992673: libgpuarray *gemv, *ger test fails

[Rebecca N. Palmer]

Control: tags -1 pending

(fixed in Salsa, as far as I consider it my bug)

It looks like both of these originate further down the stack, not in 
libgpuarray:

The *ger error code is an OpenCL compile failure from inside clblast, so 
likely either pocl or clblast.

The *gemv problem appears to be that the definition of gemv is 
y=alpha*A.dot(x)+beta*y, the spec allows and possibly requires the 
second term to be skipped entirely if beta is 0, clblas does this but 
clblast doesn't, and libgpuarray pygpu has a short form for beta=0 that 
uses an uninitialized (i.e. potentially NaN) y.  As a workaround I am 
changing this to a zero y, but it maybe should be fixed in clblast.