Remove implementation of default constructor as it is useless now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11755 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/RegAllocLinearScan.cpp

@@ -59,11 +59,6 @@ namespace {
         SpillWeights spillWeights_;
 
     public:
-        RA()
-            : prt_(NULL) {
-
-        }
-
         virtual const char* getPassName() const {
             return "Linear Scan Register Allocator";
         }