[Patch, fortran] PR34820 , PR34143 and PR32795 - some allocatable component bugs

[Dominique Dhumieres]

I still get an ICE for PR34820. Before the patch it was:

> pr34820.f90: In function 'read_grid_header':
> pr34820.f90:6: internal compiler error: in gfc_conv_descriptor_data_get, at fortran/trans-array.c:147

after it is:

< pr34820.f90: In function 'read_iregion':
< pr34820.f90:6: internal compiler error: Bus error

Dominique