Move two macros that literally doesn't change across all JIT platforms (JITDISABLE and INSTRUCTION_START) and simply have it in the JitBase.h source file. This way the macro is just located in one spot rather than 6 places.
Merge pull request #18 from lioncash/small-jit-macro-cleanup

Move two macros (JITDISABLE and INSTRUCTION_START) into JitBase.h.