Hand merge. Stuff probably doesn't compile.

Hand merge.  Stuff probably doesn't compile.

--HG--
rename : arch/alpha/isa_desc => arch/alpha/isa/main.isa
rename : arch/alpha/alpha_linux_process.cc => arch/alpha/linux/process.cc
rename : arch/alpha/alpha_linux_process.hh => arch/alpha/linux/process.hh
rename : arch/alpha/alpha_tru64_process.cc => arch/alpha/tru64/process.cc
rename : arch/alpha/alpha_tru64_process.hh => arch/alpha/tru64/process.hh
rename : cpu/exec_context.cc => cpu/cpu_exec_context.cc
rename : cpu/exec_context.hh => cpu/cpu_exec_context.hh
extra : convert_revision : 7d1efcedd708815d985a951f6f010fbd83dc27e8