It may be useful to know which named capturing groups are defined
in an regular expression, and for each of them, what's the
corresponding index. This commit adds the needed method
to QRegularExpression.
Note that extracting the information doesn't happen while holding
the mutex in the private -- pcre_fullinfo just reads information
from the compiled pattern, so that's thread-safe.
Task-number: QTBUG-29079
Change-Id: I50c00ee860f06427c2e6ea10417d5c0733cc8303
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>