QRegularExpression::wildcardToRegularExpression() docs should state it returns an anchored pattern

QRegularExpression::wildcardToRegularExpression() returns a pattern anchored with \A and \z, the issue is that the documentation doesn't mention that fact, which means that when porting code that used QRegExp::exactMatch() and QRegExp::WildCard the code could end up like this:

QRegularExpression::anchoredPattern(QRegularExpression::wildcardToRegularExpression(pattern))

which means the pattern is anchored twice, which is wrong.

This was pointed out to me by a KDE developer/contributor in a code review: https://phabricator.kde.org/D26205

Harald Sitter on IRC #kde-devel also pointed out that https://code.qt.io/cgit/qt/qtbase.git/tree/src/corelib/io/qdiriterator.cpp#n184 has the same problem.