Update order of execopts for cfd-mini-c so it works on mac w/ clang.

I don't understand why this is required, but it works.
Merge pull request #880 from thomasvandoren/fix-cfd-mini-c-on-darwin

Update order of execopts for cfd-mini-c so it works on mac w/ clang.

I don't understand why this is required, but it works. I confirmed that it still passes on
linux64, too.

r: @benharsh