Refactor dump_memory function.

- Add dumping memory around registers for x86/x86_64.
- Add unit tests for new dump_memory function.
- Cleanup all of the machine.cpp files.
- Increase the high address check for 32 bit, and decrease the high
  address allowed for 64 bit slightly to match mips64.

Bug: 21206576
(cherry picked from commit e8bc77eb845ab5557a4c98fe0da604d4a3740bef)

Change-Id: I49ec237e30076a232f084da1072bf9aba15dc0cd
diff --git a/debuggerd/machine.h b/debuggerd/machine.h
index fca9fbe..e65b147 100644
--- a/debuggerd/machine.h
+++ b/debuggerd/machine.h
@@ -19,9 +19,11 @@
 
 #include <sys/types.h>
 
+#include <backtrace/Backtrace.h>
+
 #include "utility.h"
 
-void dump_memory_and_code(log_t* log, pid_t tid);
+void dump_memory_and_code(log_t* log, Backtrace* backtrace);
 void dump_registers(log_t* log, pid_t tid);
 
 #endif // _DEBUGGERD_MACHINE_H