Revert "[trac931_2] make sure the workaround -Wno-unused-parameter follows -Wextra"
Revert "[trac931] Disable warning on one needed file"
Revert "[trac931] Missing includes"
Revert "[trac931] Test reproducing the double read bug"

This reverts commit ec644604.
This reverts commit 990a0cff.
This reverts commit 54f86d77.
This reverts commit 37ded0b3.