Workaround binutils bug by only marking unique section starting by .text._

This adds the HPPA workaround improved in
b22a0f15de36d7b69f136b75e091adca145e0251 (bootstrap: improve ld flag for
Linux/HPPA builds) not only to the bootstrap, but also to the normal build.
Merge topic 'hppa-binutils-flag' into next

9ec3e04a Workaround binutils bug by only marking unique section starting by .text._