[power-ieee128] fortran, libgfortran: Add remaining missing *_r17 symbols

[Thomas Koenig]

Hi Jakub,

> Following patch adds remaining missing *_r17 entrypoints, so that
> we have 91 *_r16 and 91 *_r17 entrypoints (and 24 *_c16 and 24 *_c17).
> 
> This fixes:
> FAIL: gfortran.dg/dec_math.f90   -O0  execution test
> FAIL: gfortran.dg/dec_math.f90   -O1  execution test
> FAIL: gfortran.dg/dec_math.f90   -O2  execution test
> FAIL: gfortran.dg/dec_math.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
> FAIL: gfortran.dg/dec_math.f90   -O3 -g  execution test
> FAIL: gfortran.dg/dec_math.f90   -Os  execution test
> FAIL: gfortran.dg/ieee/dec_math_1.f90   -O0  execution test
> FAIL: gfortran.dg/ieee/dec_math_1.f90   -O1  execution test
> FAIL: gfortran.dg/ieee/dec_math_1.f90   -O2  execution test
> FAIL: gfortran.dg/ieee/dec_math_1.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
> FAIL: gfortran.dg/ieee/dec_math_1.f90   -O3 -g  execution test
> FAIL: gfortran.dg/ieee/dec_math_1.f90   -Os  execution test
> 
> Ok for power-ieee128?

Looks good to me.

Thanks!

	Thomas