Mark dump() methods as const. NFC

Add const qualifier to any dump() method where adding one
was trivial.

Differential Revision: https://reviews.llvm.org/D34481

llvm-svn: 305963
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.h b/llvm/lib/CodeGen/LiveDebugVariables.h
index afe87a5..1d7e3d4 100644
--- a/llvm/lib/CodeGen/LiveDebugVariables.h
+++ b/llvm/lib/CodeGen/LiveDebugVariables.h
@@ -59,7 +59,7 @@
   void emitDebugValues(VirtRegMap *VRM);
 
   /// dump - Print data structures to dbgs().
-  void dump();
+  void dump() const;
 
 private: