Add an all() method to BitVector, for testing whether all bits are set.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114830 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/BitVector.h

@@ -127,6 +127,12 @@ public:
     return false;
   }
 
+  /// all - Returns true if all bits are set.
+  bool all() const {
+    // TODO: Optimize this.
+    return count() == size();
+  }
+
   /// none - Returns true if none of the bits are set.
   bool none() const {
     return !any();