Fix CUDA 7.5 nvcc compilation error in string.h

[gwtnb]

BVLC/caffe#4046

[beam2d]

Could you write down into the script briefly the reason why this line is needed?

[mitmul]

How about adding this comment right above the inserted line?

# When the gcc version is new, memcpy cannot be found in string.h
# This is a workaround for Ubuntu 16.04 environment with CUDA 7.5

[beam2d]

Then why does the issue resolved by adding _FORCE_INLINES macro?

[mitmul]

A known problem with cuda 7.5 on Ubuntu 16.4 is that gcc5.3 does not automatically deal with memcpy as it did in the past. Some people pointed out that the string.h header files are different, that is no longer true. The string.h file is correct if -D_FORCE_INLINES is passed to nvcc.
https://groups.google.com/forum/#!topic/theano-users/3ihQYiTRG4E

Work around a glibc bug
http://www.deeplearning.net/software/theano/install_ubuntu.html

Hmm, I'm not sure what the flag is exactly doing.

[beam2d]

It looks better to add a link to that discussion.

[mitmul]

Fixed the comment to make it more detailed and added links to some discussions.

[beam2d]

Thank you!