* Makefile.am (libquadmath_la_SOURCES): Add math/logbq.c.
	* Makefile.in: Regenerate.
	* libquadmath.texi: Document logbq.
	* quadmath.h: Add logbq prototype.
	* quadmath.map: Add logbq.
	* quadmath_weak.h: Add logbq prototype.
	* math/logbq.c: New file

From-SVN: r226748