s390: Floating point vector lane handling

s390: Floating point vector lane handling

Since floating point and vector registers overlap on s390, more
efficient code can be generated to extract FPRs from VRs.
Additionally, for double vectors, more efficient code can be generated
to load specific lanes.

gcc/ChangeLog:

	* config/s390/vector.md (VF): New mode iterator.
	(VEC_SET_NONFLOAT): New mode iterator.
	(VEC_SET_SINGLEFLOAT): New mode iterator.
	(*vec_set<mode>): Split pattern in two.
	(*vec_setv2df): Extract special handling for V2DF mode.
	(*vec_extract<mode>): Split pattern in two.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/vector/vec-extract-1.c: New test.
	* gcc.target/s390/vector/vec-set-1.c: New test.

Signed-off-by: Juergen Christ <jchrist@linux.ibm.com>