Committed by Kevin Buettner <kevinb@redhat.com>.
* ia64-tdep.h (ia64_write_pc, ia64_linux_write_pc): Declare.
* ia64-tdep.c (ia64_write_pc): Make it a global function.
(ia64_gdbarch_init): For Linux targets, use ia64_linux_write_pc()
instead of ia64_write_pc().
* ia64-linux-tdep.c (regcache.h): Include.
(ia64_linux_write_pc): New function.