[Bug target/63234] arm used label is removed

[mikpelinux at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63234

--- Comment #8 from Mikael Pettersson <mikpelinux at gmail dot com> ---
The failures on 4.7+ seem to be triggered by r177855, yet another ARM costing
tweak.

I'm not going to investigate this any further.