am 4fe48966: am 57c9b95b: am 39baa829: Merge "Get arm64 to compile."

* commit '4fe489665fef420210cd2e9ac1a682f8bfb950e9':
  Get arm64 to compile.
diff --git a/libbacktrace/Android.mk b/libbacktrace/Android.mk
index 9c52ad7..f23eefd 100644
--- a/libbacktrace/Android.mk
+++ b/libbacktrace/Android.mk
@@ -23,8 +23,7 @@
 	liblog \
 
 # To enable using libunwind on each arch, add it to this list.
-libunwind_architectures :=
-#libunwind_architectures := arm
+libunwind_architectures := arm64
 
 ifeq ($(TARGET_ARCH),$(filter $(TARGET_ARCH),$(libunwind_architectures)))
 
diff --git a/libbacktrace/UnwindCurrent.cpp b/libbacktrace/UnwindCurrent.cpp
index 747eb21..d1195ee 100644
--- a/libbacktrace/UnwindCurrent.cpp
+++ b/libbacktrace/UnwindCurrent.cpp
@@ -43,7 +43,7 @@
   #include <asm/sigcontext.h>
   #include <asm/ucontext.h>
   typedef struct ucontext ucontext_t;
-#elif !defined(__mips__)
+#elif !defined(__mips__) && !defined(__aarch64__)
   #error Unsupported architecture.
 #endif