Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC: r257315, r260445, r264803

Update byacc to 20140422

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Update byacc to 20130304

Import byacc from invisible island, it brings us lots of compatibilities with
bison, keeping full compatibility with our previous yacc implementation.

Also bring the ability to create reentrant parser

This fix bin/140309 [1]

PR: bin/140309 [1]
Submitted by: Philippe Pepiot <ksh@philpep.org> [1]
Approved by: des (mentor)
MFC after: 1 month

Import byacc 20120115

Approved by: des (mentor)