DWARF and unwind support for AOT assembly output.

runtime/vm/native_symbol_linux.cc

Index: runtime/vm/native_symbol_linux.cc
diff --git a/runtime/vm/native_symbol_linux.cc b/runtime/vm/native_symbol_linux.cc
index 9556ddb615825005011224b7fd38a019bba9de98..aac30172d706919294cee513c05f705682bb6d2b 100644
--- a/runtime/vm/native_symbol_linux.cc
+++ b/runtime/vm/native_symbol_linux.cc
@@ -47,6 +47,19 @@ void NativeSymbolResolver::FreeSymbolName(char* name) {
 }
 
 
+bool NativeSymbolResolver::LookupSharedObject(uword pc,
+                                              uword* dso_base,
+                                              char** dso_name) {
+  Dl_info info;
+  int r = dladdr(reinterpret_cast<void*>(pc), &info);
+  if (r == 0) {
+    return false;
+  }
+  *dso_base = reinterpret_cast<uword>(info.dli_fbase);
+  *dso_name = strdup(info.dli_fname);
+  return true;
+}
+
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)