NVidia issues

[rylimaki]

Three test cases fail on Linux/NVidia because of possible driver bugs (nvidia-319/319.32-0ubuntu7). These can't be probably fixed in the validator but should be documented.

1. private_mem_zeroing.cl

PrivateStruct fields are initialized correctly. The alignment bytes of char and char* members contain usually garbage.

2. relocate-variables.cl

$ opencl-validator < relocate-variables.cl

opencl-validator: Compiling input for NVIDIA CUDA/GeForce GTX 770.
Stack dump:
0. Running pass 'Function Pass Manager' on module ''.

1.  Running pass 'Combine redundant instructions' on function '@relocate_variables'
   

Segmentation fault (core dumped)

3. remove-variables.cl

$ webcl-validator remove-variables.cl | opencl-validator

warning: argument unused during compilation: '-fsyntax-only'
opencl-validator: Compiling input for NVIDIA CUDA/GeForce GTX 770.
opencl-validator: Can't build OpenCL program.
ptxas application ptx input, line 11; error : Unimplemented feature: labels as initial values
...
ptxas application ptx input, line 11; error : Variable used as initial value not in .global or .const state space
...
ptxas application ptx input, line 11; error : Label expected for forward reference of '_wcl_constant_allocations'
...

[elhigu]

Nvidia driver on OSX Mavericks also fail pretty badly. I should try soonish if windows driver works better.