OpenJDK fails to build with the following compile error:

/build/reproducible-path/openjdk-25-25~15ea/src/hotspot/os_cpu/linux_ppc/javaThread_linux_ppc.cpp: In member function ‘bool JavaThread::pd_get_top_frame_for_profiling(frame*, void*, bool)’:
/build/reproducible-path/openjdk-25-25~15ea/src/hotspot/os_cpu/linux_ppc/javaThread_linux_ppc.cpp:51:37: error: incomplete type ‘os::Linux’ used in nested name specifier
   51 | intptr_t* top_sp = os::Linux::ucontext_get_sp((const ucontext_t*)ucontext);
      | ^~~~~~~~~~~~~~~

See https://buildd.debian.org/status/fetch.php?pkg=openjdk-25&arch=ppc64&ver=25%7E15ea-1&stamp=1742768056&raw=0