Fix android for large builds

[thomasuster]

TLDR, this fixes large android builds from crashing during the link step.

Details: It took me a very long time to get this working, and I wasn't able to discover why exactly this occurs. What is interesting about this step of the build is that the output for the program I'm linking is large, >200,000 characters. So originally I tried making the hxcache dir path as short as possible. When that didn't work I looked into ulimits, launchctrl, and tried looking at any kind of diagnostics that OSX has builtin. Ultimately I was unsuccessful. As a shot in the dark, I tried writing the command HXCPP was about to run to a temporary .sh file, and then invoked that sh file and was surprised to see that it worked. To me that signaled perhaps the problem is the stdout / stdin trying to get the data back into the NekoVM. There is probably some more beautiful way to fix this, either in neko VM, or some bizaare OSX environment option I wasn't able to find.