[Patch, Fortran] Add end-of-scope finalization (Part 2 of 2)

[Tobias Burnus]

Dear Dominique,

Dominique Dhumieres wrote:
> Failures in 32 bit mode again!-(
> FAIL: gfortran.dg/finalize_18.f90  -O   scan-tree-dump-times original "y.cc._vptr->_final \\(&desc.5, \\(integer\\(kind=8\\)\\) y.cc._vptr->_size, 1\\);" 1

I will fix those before committal.

> /opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90: In function '__final_test2_T.2138.constprop.0':
> /opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90:39:0: warning: iteration 2147483648 invokes undefined behavior [-Waggressive-loop-optimizations]
>       class(t), allocatable :: a
>   ^

I have not fully understood why this happens. It seems to have something 
to do with cloning/const propagation. Looking at the original dump, the 
optimized dump at -O0, -O2 and -O3 - and at the FE code -, I believe the 
generated code is correct.

The cloning propagates the rank == 1 into the cloned finalizer, which 
permits to drastically simplify the scalarizer. That allows to remove 
one loop (the one which is warned about?) and to simplify another loop 
into a single trip.

Thus, my working hypothesis is that either the warning is wrong or that 
something goes wrong with the loop optimization, triggering the warning.

Tobiashhhhh