tree dcac88e1069f62802a4c8bb659224dd5ebe6e23e
parent c84688961e2c6f8d15854d32cffbf4bb8f1da0db
author Damien Neil <dneil@google.com> 1536338384 -0700
committer Damien Neil <dneil@google.com> 1536343057 +0000

reflect: add Index method to descriptor

Useful for dealing with SourceCodeInfo location paths, which identify
entities by their index.

Change-Id: I2034fc06b14c9b29b26e356fad21e106f63fbd14
Reviewed-on: https://go-review.googlesource.com/134115
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>