ScopInfo: Make printing of ScopArrayInfo more similar to declarations in C

Memory references are now printed as follows:

           Old                          New
Scalars:   i64 MemRef_val[*]            i64 MemRef_val;
Arrays:    i64 MemRef_A[*][%m][%o][8]   i64 MemRef_A[*][%m][%o];

We do not print any more information about the element size in the type. Such
information has already been available in a comment after the scalar/array
declaration. It was redundant and did not match well with what people were used
from C.

llvm-svn: 252602