Be more careful when rewriting thick pointer array type

Be more careful when rewriting thick pointer array type

To handle thick pointers with -fgnat-encodings=minimal, gdb will
rewrite the underlying array type to remove the bounds.  However, if
the same DWARF type is used both for a thick pointer and for an
ordinary array, this will have the side effect of removing the bounds
from the array.  This breaks the printing of objects of this type.

This patch fixes the problem by copying the array type, its range, and
its bounds.

gdb/ChangeLog
2020-12-14  Tom Tromey  <tromey@adacore.com>

	* dwarf2/read.c (rewrite_array_type): New function.
        (quirk_ada_thick_pointer_struct): Use rewrite_array_type.

gdb/testsuite/ChangeLog
2020-12-14  Tom Tromey  <tromey@adacore.com>

	* gdb.dwarf2/ada-thick-pointer.exp: New file.