There are many cases where we need |BN_rand_range| but with a minimum
value other than 0. |BN_rand_range_ex| provides that.
Change-Id: I564326c9206bf4e20a37414bdbce16a951c148ce
Reviewed-on: https://boringssl-review.googlesource.com/8921
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>