re PR fortran/17283 (UNPACK issues)

re PR fortran/17283 (UNPACK issues)

PR fortran/17283
fortran/
* iresolve.c (gfc_resolve_pack): Choose function depending if mask is
scalar.
libgfortran/
* intrinsics/pack_generic.c (__pack): Allocate memory for return array
if not done by caller.
(__pack_s): New function.
* runtime/memory.c (internal_malloc, internal_malloc64): Allow
allocating zero memory.
testsuite/
* gfortran.fortran-torture/execute/intrinsic_pack.f90: Add more tests.

From-SVN: r88526