Weight variables by their number of uses for register allocation.

src/IceOperand.cpp

Index: src/IceOperand.cpp
diff --git a/src/IceOperand.cpp b/src/IceOperand.cpp
index e46fac03d9387604f3d1a0fea6fc48bb37c49713..00b9c1d305b7d62bd6827b54210f596aafb2298b 100644
--- a/src/IceOperand.cpp
+++ b/src/IceOperand.cpp
@@ -466,7 +466,6 @@ void ConstantUndef::emit(TargetLowering *Target) const { Target->emit(this); }
 void LiveRange::dump(Ostream &Str) const {
   if (!BuildDefs::dump())
     return;
-  Str << "(weight=" << Weight << ") ";
   bool First = true;
   for (const RangeElementType &I : Range) {
     if (!First)