[PATCH] [libcxxabi] Make _Unwind_Backtrace() work on ARM.

[Jon Roelofs]

with the assert added back, LGTM.

I'll think about how to make the asserts tighter, and we can come back & fix up the test case if there ends up being a better way to do that.

================
Comment at: src/Unwind/Unwind-EHABI.cpp:174
@@ +173,3 @@
+  size_t off = 0;
+  unwindingData = decode_eht_entry(unwindingData, &off, &len);
+  if (unwindingData == nullptr) {
----------------
assert((*unwindingData & 0xf0000000) == 0x80000000 && "Must be a compact entry");

http://reviews.llvm.org/D5112