gfortran.dg/gomp/depend-6.f90: minor fix + dump update

gfortran.dg/gomp/depend-6.f90: minor fix + dump update

Contains the minor fix of upstream commit
r13-2152-gf05e3b2c63f3307ba405900f1a80c25b2e87b0a3
to avoid setting the same array element twice, which is:
Exactly the same as previous commit for depend-4.f90, r13-2151.

Additionally, it updates the expected tree dumps due to differences
between GCC 12/OG12 and mainline (GCC13); the latter seems to
use a restricted pointer of type '&a[1]' while OG12 has pointerplus
expressions like 'a + 4'.

The changes include -m32/-m64 handling for the depobj var and in
two cases, the expected count increases from 1 to 2 for code like
'D.\[0-9\]+ = daa'.

The latter is likewise the same as done for depend-4.f90 on the OG12
branch in commit d77133b29fc51de4e0f37de5f6ad2b5496124346-

gcc/testsuite/
	* gfortran.dg/gomp/depend-6.f90: Update expected tree dumps.