A few cases of matrix multiplication weren't working properly
due to using the wrong matrix dimension. For example, if we
have the following matrix operation (using matColRow):
mat32 = mat22 * mat32
This results in 3 multiplication of 2 element vectors for each
row of the result and the current code (before this cl) would
only perform 2 multiplications and produce the wrong result.

This cl should fix all uses of the * operator and of the
matrixCompMult function when using non square matrices.

Change-Id: Id0dbfd9d65c20102220049c34435c37e3db7f9da
Reviewed-on: https://swiftshader-review.googlesource.com/3966Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>