[14/77] Make libgcc_floating_mode_supported_p take a scalar_float_mode

[14/77] Make libgcc_floating_mode_supported_p take a scalar_float_mode

As per subject.

2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* target.def (libgcc_floating_mode_supported_p): Take a
	scalar_float_mode.
	* doc/tm.texi: Regenerate.
	* targhooks.h (default_libgcc_floating_mode_supported_p): Take a
	scalar_float_mode.
	* targhooks.c (default_libgcc_floating_mode_supported_p): Likewise.
	* config/aarch64/aarch64.c (aarch64_libgcc_floating_mode_supported_p):
	Likewise.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r251466