make check fail

[iza...@gmail.com]

Hi everyone,

I am running macosx11, I found the readme file point out ' The OpenCL included with Mac OS X has several bugs that lead to failures in some of the Harlan test cases. For the most part, these failures can be ignored.' But how can I distinguish errors can be ignored?

I run `make check` then got these output:
```
......
Creating queue for Intel(R) Core(TM) i7-3615QM CPU @ 2.30GHz
OpenCL Error: OpenCL Build Warning : Compiler build log:
<program source>:178:16: warning: no previous prototype for function 'bottom'
weight$dt_8994 bottom() {
^
......
Creating queue for Intel(R) Core(TM) i7-3615QM CPU @ 2.30GHz
OpenCL Error: OpenCL Build Warning : Compiler build log:
<program source>:158:13: warning: unused variable 'i_27429'
int i_27429 = get_global_id(0);
^

freeing region 0x10feea000. 80 bytes of 8388608 allocated
freeing region 0x110eea000. 64 bytes of 8388608 allocated
freeing region 0x111eea000. 120 bytes of 8388608 allocated
[0 1 2 3 4 5 6 7]
FAILED
.......
Some tests failed:
test/scan.kfc
test/graph-holography.kfc
Successes: 158; Failures: 2; Ignored: 30; Total: 190
```

I haven't installed Intel OpenCL SDK. But I installed CUDA, and enabled my GPU card. It seems harlan cannot detect my video card.

Then I tried `HARLAN_DEVICE=gpu make check` then I got more errors:

```
Some tests failed:
test/unsafe-vec-ptr.kfc
test/read-file.kfc
test/raytrace.kfc
test/nbody2.kfc
test/nbody.kfc
test/kernel-even-odd.kfc
test/interp-lambda2.kfc
Successes: 153; Failures: 7; Ignored: 30; Total: 190
```

So How can I indicate GPU to use?