Microdumps: support aarch64 and lib mapping from APK

- Filter modules by prot flags (only +x) not extensions. It wouldn't
  otherwise catch the case of Chrome mapping the library from the
  apk (which is mapped r-x but doesn't end in .so).
- Use compile-time detection of target arch, in order to cope with
  multilib OSes, where uname() doesn't reflect the run-time arch.
- Add OS information and CPU arch / count.
- Add support for aarch64.
- Add tests and stackwalk expectations for aarch64.
- Fix a potential overflow bug in the processor.
- Rebaseline the tests using smaller symbols.
- Fix microdump_writer_unittest.cc on 32-bit host.

BUG=chromium:410294

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1407 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/google_breakpad/processor/microdump.h

@@ -46,6 +46,7 @@
 #include "common/using_std_string.h"
 #include "google_breakpad/processor/dump_context.h"
 #include "google_breakpad/processor/memory_region.h"
+#include "google_breakpad/processor/system_info.h"
 #include "processor/basic_code_modules.h"
 
 namespace google_breakpad {
@@ -64,6 +65,7 @@ class MicrodumpModules : public BasicCodeModules {
 class MicrodumpContext : public DumpContext {
  public:
   virtual void SetContextARM(MDRawContextARM* arm);
+  virtual void SetContextARM64(MDRawContextARM64* arm64);
 };
 
 // This class provides access to microdump memory regions.
@@ -109,11 +111,13 @@ class Microdump {
   DumpContext* GetContext() { return context_.get(); }
   MicrodumpMemoryRegion* GetMemory() { return stack_region_.get(); }
   MicrodumpModules* GetModules() { return modules_.get(); }
+  SystemInfo* GetSystemInfo() { return system_info_.get(); }
 
  private:
   scoped_ptr<MicrodumpContext> context_;
   scoped_ptr<MicrodumpMemoryRegion> stack_region_;
   scoped_ptr<MicrodumpModules> modules_;
+  scoped_ptr<SystemInfo> system_info_;
 };
 
 }  // namespace google_breakpad