We plan to make GOEXPERIMENT=framepointer the default for the Go 1.7 beta 1,
as a trial balloon toward leaving it on for the Go 1.7 release.
There is a small performance hit to having frame pointers enabled
(typically 1-3%), but this release brings with it significantly more
than that due to SSA, so we have the budget available to do this without
slowing down user programs compared to the previous release.

Having frame pointers on by default means that Linux perf, Intel VTune,
and other profilers can grab Go stack traces much more efficiently,
making the profiles significantly more reflective of reality.
This is a good default to have. The performance work enabled by this
probably also significantly outweighs the slowdown.

/cc @aclements @randall77