New expf and exp2f version without SVID compat wrapper

This patch changes the expf and exp2f error handling semantics to only
set errno accoring to POSIX rules. New symbol version is introduced at
GLIBC_2.27.

The old wrappers are kept for compat symbols.

Internal calls to __expf now get the new error semantics, this seems to
only affect sysdeps/i386/fpu/s_expm1f.S where the errno-only behaviour
should be correct.

ia64 needed assembly change to have the new and compat versioned symbol
map to the same function.

All linux libm abilists are updated.

	* math/Versions (expf): New libm symbol at GLIBC_2.27.
	(exp2f): Likewise.
	* math/w_exp2f.c: New file.
	* math/w_expf.c: New file.
	* math/w_exp2f_compat.c (__exp2f_compat): For compat symbol only.
	* math/w_expf_compat.c (__expf_compat): Likewise.
	* sysdeps/ia64/fpu/e_exp2f.S: Add versioned symbols.
	* sysdeps/ia64/fpu/e_expf.S: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Update.
	* 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.