Add fmaxmag, fminmag functions.

Add fmaxmag, fminmag functions.

TS 18661-1 defines fmaxmag and fminmag functions that return the
argument with maximum / minimum magnitude (acting like fmax / fmin if
the arguments have the same magnitude or either argument is a NaN).
These correspond to the IEEE 754-2008 operations maxNumMag and
minNumMag.  This patch implements these functions for glibc.  They are
implemented with type-generic templates.  Tests are based on those for
fmax and fmin.

Tested for x86_64, x86, mips64 and powerpc.

	* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
	(fmaxmag): New declaration.
	(fminmag): Likewise.
	* math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (fmaxmag): New
	macro.
	[__GLIBC_USE (IEC_60559_BFP_EXT)] (fminmag): Likewise.
	* math/Versions (fmaxmag): New libm symbol at version GLIBC_2.25.
	(fmaxmagf): Likewise.
	(fmaxmagl): Likewise.
	(fminmag): Likewise.
	(fminmagf): Likewise.
	(fminmagl): Likewise.
	* math/Makefile (gen-libm-calls): Add s_fmaxmagF and s_fminmagF.
	* math/s_fmaxmag_template.c: New file.
	* math/s_fminmag_template.c: Likewise.
	* math/libm-test.inc (fmaxmag_test_data): New array.
	(fmaxmag_test): New function.
	(fminmag_test_data): New array.
	(fminmag_test): New function.
	(main): Call fmaxmag_test and fminmag_test.
	* math/test-tgmath.c (NCALLS): Increase to 132.
	(F(compile_test)): Call fmaxmag and fminmag.
	(F(fminmag)): New function.
	(F(fmaxmag)): Likewise.
	* manual/arith.texi (Misc FP Arithmetic): Document fminmag,
	fminmagf, fminmagl, fmaxmag, fmaxmagf and fmaxmagl.
	* manual/libm-err-tab.pl (@all_functions): Add fmaxmag and
	fminmag.
	* sysdeps/ieee754/ldbl-opt/nldbl-fmaxmag.c: New file.
	* sysdeps/ieee754/ldbl-opt/nldbl-fminmag.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_fmaxmagl.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_fminmagl.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add fmaxmag
	and fminmag.
	(CFLAGS-nldbl-fmaxmag.c): New variable.
	(CFLAGS-nldbl-fminmag.c): Likewise.
	* sysdeps/nacl/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.