Update vendorized Spike tree and Spike-related components.
Created by: zchamski
Upgrade the vendorized Spike tree to version fcbdbe7946079650d0e656fa3d353e3f652d471f:
- create vendorized patches on top of previous Spike version
- upgrade Spike source tree
- update patches to match the upgraded tree
- update CV-X-IF extension code
- consistently use C++ 2017 standard for C++ code.