Move Log from Core -> Utility.

All references to Host and Core have been removed, so this
class can now safely be lowered into Utility.

Differential Revision: https://reviews.llvm.org/D30559

llvm-svn: 296909
diff --git a/lldb/source/Expression/ExpressionVariable.cpp b/lldb/source/Expression/ExpressionVariable.cpp
index 00e6896..a971800 100644
--- a/lldb/source/Expression/ExpressionVariable.cpp
+++ b/lldb/source/Expression/ExpressionVariable.cpp
@@ -8,8 +8,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "lldb/Expression/ExpressionVariable.h"
-#include "lldb/Core/Log.h"
 #include "lldb/Expression/IRExecutionUnit.h"
+#include "lldb/Utility/Log.h"
 
 using namespace lldb_private;