I recently pushed two patches upstream related to the enablement of ISA 3.0 (POWER9) instructions. The first one, commit 526f342, enables instructions in the assembler. This includes new compares, loads, math operations, register moves, the new random number generator and the new copy/paste facility.
The second one, commit 6661cf6, enables the new internal/cpu package for Power. This package provides runtime CPU identification and capabilities detection and we will use it to write new runtime performance optimizations specific for POWER9 without breaking the code for POWER8.
Both will be available in go1.10. Or you can grab the current upstream code and build it yourself to use them.