[clang] [llvm] [AVR] Handle flash RO data mapped to data space for newer devices (PR #146244)

[Tom Vijlbrief via cfe-commits]

tomtor wrote:

@benshi There is an alternative to new driver options: https://github.com/llvm/llvm-project/pull/146244/files#r2179646110

That would be a minimal change, and a general improvement giving users more options to tune the linking.

https://github.com/llvm/llvm-project/pull/146244