Fixed bignum.c and bn_mul.h to support Thumb2 and LLVM compiler
diff --git a/include/polarssl/bn_mul.h b/include/polarssl/bn_mul.h
index cffcd6b..1c2da13 100644
--- a/include/polarssl/bn_mul.h
+++ b/include/polarssl/bn_mul.h
@@ -548,7 +548,7 @@
 
 #if defined(__arm__)
 
-#if defined(__thumb__)
+#if defined(__thumb__) && !defined(__thumb2__)
 
 #define MULADDC_INIT                            \
     asm(                                        \