What % of the time are you gaming vs programming?
Upgrading the CPU will have a 0-5% increase in gaming performance.
Upgrading the CPU will have a 2x the performance in CPU encoding/compiling.
Upgrading the GPU will have a substatial performance increase in gaming.
Upgrading the GPU will have a 0% increase in (nearly) everything else.
If you mostly game, upgrade the GPU. The 8370 will not bottleneck most games until you get to a 980 Ti, 1070 or above. Until you actually have a 1070, or Vega, upgrading the CPU is basically pointless for gaming.
If you mostly do programming with a side of gaming, Ryzen over FX will offer 2x the performance. Don’t bother upgrading the GPU since CPU compiling will show a 0% improvement with a better GPU.
Don’t expect games to be any better when using Ryzen over FX.
Related threads: Nvidia GeForce GTX 1050 Ti Scaling with FX and Ryzen on Windows 10 and AMD FX 8350 versus AMD Ryzen 7 1700 Scaling on Windows 10