re PR fortran/46625 (libquadmath: Mangle internal symbols; rename __float128 <-> string functions)

	PR fortran/46625
	* quadmath.map (QUADMATH_1.0): Remove quadmath_strtopQ
	and quadmath_dtoaq.  Add strtoflt128 and quadmath_flt128tostr.
	* quadmath_weak.h (quadmath_strtopQ, quadmath_dtoaq): Remove.
	(strtoflt128, quadmath_flt128tostr): Add.
	* gdtoa/strtopQ.c (quadmath_strtopQ): Rename to...
	(strtoflt128): ... this.  Return __float128, instead of writing
	to memory pointed by last argument.
	* quadmath.h: Use C style comments instead of C++ style.
	(quadmath_strtopQ, quadmath_dtoaq): Remove prototypes.
	(strtoflt128, quadmath_flt128tostr): Add prototypes.
	* libquadmath.texi (quadmath_dtoaq): Rename to quadmath_flt128tostr.
	(quadmath_strtopQ): Rename to strtoflt128.  Adjust prototype,
	adjust examples.
	* quadmath_io.c (quadmath_dtoaq): Rename to...
	(quadmath_flt128tostr): ... this.
libgfortran/
	* io/write_float.def (DTOAQ): Use quadmath_flt128tostr
	instead of quadmath_dtoa.
	* io/transfer128.c (tmp1, tmp2): New variables, bring in
	strtoflt128 and quadmath_flt128tostr.
	(transfer_real128, transfer_real128_write, transfer_complex128,
	transfer_complex128_write): Remove tmp1/tmp2 variables.
	* io/read.c (convert_real): Use strtoflt128 instead of
	quadmath_strtopQ, adjust for the changed arguments and return
	value.

From-SVN: r168856