[Go] using efence to debug memory access violation

Reference:
efence and changing the read-validity of memory pages on darwin/amd64

https://pkg.go.dev/runtime?tab=doc#hdr-Environment_Variables
efence: setting efence=1 causes the allocator to run in a mode
where each object is allocated on a unique page and addresses are
never recycled.

man efence: https://linux.die.net/man/3/efence

In efence mode that already happens for large allocations.  See the
calls to sysFault in the runtime package.
https://github.com/golang/go/blob/master/src/runtime/mem_linux.go#L152