Simple renaming: CPUOldState -> CPUArchState where relevant.

This patch changes a few headers and sources to match upstream when
distinguishing between CPUArchState and CPUOldState (which will become
CPUState soon). For now, both types are identical so this should not
change the generated binaries at all.

Change-Id: I738b4ccaf75838a5931538dd52d1873750f1b816
diff --git a/cpu-exec.c b/cpu-exec.c
index f7a1b09..d658576 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -65,7 +65,7 @@
 /* exit the current TB from a signal handler. The host registers are
    restored in a state compatible with the CPU emulator
  */
-void cpu_resume_from_signal(CPUOldState *env1, void *puc)
+void cpu_resume_from_signal(CPUArchState *env1, void *puc)
 {
 #if !defined(CONFIG_SOFTMMU)
 #ifdef __linux__