ICE on valid with null pointer initialization

[Dominique Dhumieres]

There is no segmentation fault at revision 177649 and gdb shows

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000000
0x0000000141df2684 in __gmpz_clear ()
(gdb) bt
#0  0x0000000141df2684 in __gmpz_clear ()
#1  0x000000010002a0bc in gfc_clear_shape (shape=<value temporarily unavailable, due to optimizations>, rank=<value temporarily unavailable, due to optimizations>) at ../../work/gcc/fortran/expr.c:405

So the problem is likely caused/exposed by revision 177970 for pr50050.

Cheers,

Dominique