[PATCH v2] sh: Correct NaN signalling bit and propagation rules [PR111814]

[PATCH v2] sh: Correct NaN signalling bit and propagation rules [PR111814]

As per architecture, SuperH has a reversed NaN signalling bit
vs IEEE754-2008, it also has a NaN propgation rule similar to
MIPS style.

Use mips style float format and mode for all float types, and
correct sfp-machine header accordingly.

	PR target/111814

gcc/ChangeLog:

	* config/sh/sh-modes.def (RESET_FLOAT_FORMAT): Use mips format.
	(FLOAT_MODE): Use mips mode.

libgcc/ChangeLog:

	* config/sh/sfp-machine.h (_FP_NANFRAC_B): Reverse signaling bit.
	(_FP_NANFRAC_H): Likewise.
	(_FP_NANFRAC_S): Likewise.
	(_FP_NANFRAC_D): Likewise.
	(_FP_NANFRAC_Q): Likewise.
	(_FP_KEEPNANFRACP): Enable for target.
	(_FP_QNANNEGATEDP): Enable for target.
	(_FP_CHOOSENAN): Port from MIPS.

gcc/testsuite/ChangeLog:

	* gcc.target/sh/pr111814.c: New test.