Implemented matrix transpose

Implemented matrix transpose for
uniform matrices. Also found and
fixed a minor issue in OutputASM
which was causing a bad GL error.

Change-Id: I2d6c603770548c60e56d417b240ca276ec33ba45
Reviewed-on: https://swiftshader-review.googlesource.com/3191
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>