Added a #define for running tests without file access.
Added a #define for running tests without file access.

Change-Id: Ib2b7aa8a5641cf73fa0d6f2000db7fdd1aabab66
Tested: on Linux.

ThomasBrixLarsen/flatbuffers,ThomasBrixLarsen/flatbuffers,ThomasBrixLarsen/flatbuffers,ThomasBrixLarsen/flatbuffers,ThomasBrixLarsen/flatbuffers,ThomasBrixLarsen/flatbuffers