Trying to get CUDA 7.5 to work with GCC 5.x

So, if you try to use nvcc when the system GCC is version 5 and up, you get an "unsupported version" error. But - I've heard people report that they've just commented this out and that CUDA 7.5 "works for them" with GCC 5.x .

When I do the same, however (the check is in $CUDA_DIR/host_config.h), and compile something, I get the following errors:

/usr/lib/gcc/x86_64-redhat-linux/5.3.1/include/mwaitxintrin.h(36): error: identifier "__builtin_ia32_monitorx" is undefined
/usr/lib/gcc/x86_64-redhat-linux/5.3.1/include/mwaitxintrin.h(42): error: identifier "__builtin_ia32_mwaitx" is undefined

and a bunch of others, but those may be dependent on these. Now, these are MMX-related intrinsics for X86 architectures. I don't use them directly, so I'm guessing they're opted-in somehow. Perhaps this can be avoided?

Is there a way to overcome these errors and actually get GCC 5 to coexist with CUDA 7.5? And for code to build and run?

Notes:

• I've read a suggestion to use -D__STRICT_ANSI__. I have, and it doesn't seem to help.
• I'm on Fedora 22 in case it matters.

It's essentially futile to try to get GCC 5.x to work with CUDA 7.5 - there are some (or many?) incompatiblity issues which you simply can't resolve. Instead, just upgrade to CUDA 8.0 which has become available since this question was asked.