Fix a bug in the densemap that was killing the local allocator, and probably

other clients.  The problem is that the nullVal member was left to the default
constructor to initialize, which for int's does nothing (ie, leaves it unspecified).

To get a zero value, we must use T().  It's C++ wonderful? :)

llvm-svn: 11867

include/Support/DenseMap.h

@@ -33,7 +33,7 @@ class DenseMap {
     ToIndexT toIndex_;
 
 public:
-    DenseMap() { }
+    DenseMap() : nullVal_(T()) { }
 
     explicit DenseMap(const T& val) : nullVal_(val) { }