re PR target/85456 (PowerPC: Using -mabi=ieeelongdouble calls wrong function for...

re PR target/85456 (PowerPC: Using -mabi=ieeelongdouble calls wrong function for __builtin_powi.)

[libgcc]
2018-04-20  Michael Meissner  <meissner@linux.ibm.com>

	PR target/85456
	* config/rs6000/_powikf2.c: New file.  Add support for the
	__builtin_powil function when long double is IEEE 128-bit floating
	point.
	* config/rs6000/float128-ifunc.c (__powikf2_resolve): Add
	__powikf2 support.
	(__powikf2): Likewise.
	* config/rs6000/quad-float128.h (__powikf2_sw): Likewise.
	(__powikf2_hw): Likewise.
	(__powikf2): Likewise.
	* config/rs6000/t-float128 (fp128_ppc_funcs): Likewise.
	* config/rs6000/t-float128-hw (fp128_hw_func): Likewise.
	(_powikf2-hw.c): Likewise.

[gcc]
2018-04-20  Michael Meissner  <meissner@linux.ibm.com>

	PR target/85456
	* config/rs6000/rs6000.c (init_float128_ieee): Add support to call
	__powikf2 when long double is IEEE 128-bit.

[gcc/testsuite]
2018-04-20  Michael Meissner  <meissner@linux.ibm.com>

	PR target/85456
	* gcc.target/powerpc/pr85456.c: New test.

From-SVN: r259533