When more than three multiplications are chained, Intel’s Windows
driver returns a mat4 containing only zeroes, likely due to a
misbehaving optimisation.  This patch prevents it from doing any
optimisation by doing each multiplication in its own uniform block.

Change-Id: I0b435d3a5444afd47f78c379f0d2e442d2c2cfc0
Reviewed-on: https://gerrit.libreoffice.org/22470Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>