s390: Implement isfinite and isnormal optabs

Merge new optabs with the existing implementations for signbit and
isinf.

gcc/ChangeLog:

	* config/s390/s390.h (S390_TDC_POSITIVE_ZERO): Remove.
	(S390_TDC_NEGATIVE_ZERO): Remove.
	(S390_TDC_POSITIVE_NORMALIZED_BFP_NUMBER): Remove.
	(S390_TDC_NEGATIVE_NORMALIZED_BFP_NUMBER): Remove.
	(S390_TDC_POSITIVE_DENORMALIZED_BFP_NUMBER): Remove.
	(S390_TDC_NEGATIVE_DENORMALIZED_BFP_NUMBER): Remove.
	(S390_TDC_POSITIVE_INFINITY): Remove.
	(S390_TDC_NEGATIVE_INFINITY): Remove.
	(S390_TDC_POSITIVE_QUIET_NAN): Remove.
	(S390_TDC_NEGATIVE_QUIET_NAN): Remove.
	(S390_TDC_POSITIVE_SIGNALING_NAN): Remove.
	(S390_TDC_NEGATIVE_SIGNALING_NAN): Remove.
	(S390_TDC_POSITIVE_DENORMALIZED_DFP_NUMBER): Remove.
	(S390_TDC_NEGATIVE_DENORMALIZED_DFP_NUMBER): Remove.
	(S390_TDC_POSITIVE_NORMALIZED_DFP_NUMBER): Remove.
	(S390_TDC_NEGATIVE_NORMALIZED_DFP_NUMBER): Remove.
	(S390_TDC_SIGNBIT_SET): Remove.
	(S390_TDC_INFINITY): Remove.
	* config/s390/s390.md (signbit<mode>2<tf_fpr>): Merge this one
	(isinf<mode>2<tf_fpr>): and this one into
	(<TDC_CLASS:tdc_insn><mode>2<tf_fpr>): new expander.
	(isnormal<mode>2<tf_fpr>): New BFP expander.
	(isnormal<mode>2): New DFP expander.
	* config/s390/vector.md (signbittf2_vr): Merge this one
	(isinftf2_vr): and this one into
	(<tdc_insn>tf2_vr): new expander.
	(signbittf2): Merge this one
	(isinftf2): and this one into
	(<tdc_insn>tf2): new expander.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/isfinite-isinf-isnormal-signbit-1.c: New test.
	* gcc.target/s390/isfinite-isinf-isnormal-signbit-2.c: New test.
	* gcc.target/s390/isfinite-isinf-isnormal-signbit-3.c: New test.
	* gcc.target/s390/isfinite-isinf-isnormal-signbit.h: New test.