g++-4.3 build-fix: CHAR_BIT requires <climits>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49989 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/InstructionCombining.cpp

@@ -57,6 +57,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
 #include <algorithm>
+#include <climits>
 #include <sstream>
 using namespace llvm;
 using namespace llvm::PatternMatch;