Included assert.h so that the code compiles under newer versions of GCC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6682 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineInstr.h

@@ -13,6 +13,8 @@
 #include "Support/Annotation.h"
 #include "Support/iterator"
 #include <set>
+#include <assert.h>
+
 class Value;
 class Function;
 class MachineBasicBlock;