[c++] add some required arm symbols for c++

lib/libc/atexit.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008 Travis Geiselbrecht
+ * Copyright (c) 2008-2015 Travis Geiselbrecht
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files

lib/libc/eabi.c

@@ -23,6 +23,8 @@
 /* some cruft we have to define when using the linux toolchain */
 #include <unwind.h>
 
+void *__dso_handle;
+
 #if defined(__ARM_EABI_UNWINDER__) && __ARM_EABI_UNWINDER__
 
 /* Our toolchain has eabi functionality built in, but they're not really used.
@@ -49,3 +51,12 @@ void raise(void)
 {
 }
 
+extern int __cxa_atexit(void (*func)(void *), void *arg, void *d);
+
+int __aeabi_atexit(void *arg, void (*func)(void *), void *d)
+{
+    return __cxa_atexit(func, arg, d);
+}
+
+
+

lib/libc/pure_virtual.cpp

@@ -27,3 +27,8 @@ extern "C" void __cxa_pure_virtual(void)
     panic("pure virtual called\n");
 }
 
+extern "C" int __cxa_atexit(void (*destructor)(void *), void *arg, void *__dso_handle)
+{
+    return 0;
+}
+