cmd/guru: emacs: add function for expandiong region
cmd/guru: emacs: add function for expandiong region

The go-guru-expand-region function uses the "what" query to determine
the enclosing regions. Consecutive calls to go-guru-expand-region will
reuse a cached version of the list.

Change-Id: Ice9ac5540c1b639c6cbdc505866bbab347be1e98
Reviewed-on: https://go-review.googlesource.com/21754
Reviewed-by: Alan Donovan <7069e9552f9d110b0a0f326b96f22f63fb99dfc1@google.com>

syreclabs/go-tools,syreclabs/go-tools,golang/tools,golang/tools,syreclabs/go-tools,golang/tools,syreclabs/go-tools,syreclabs/go-tools,golang/tools,golang/tools,syreclabs/go-tools