Move the vtable builder to CGVtable.cpp, general cleanup.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83798 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index 0fd7652..fc24144 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -413,7 +413,7 @@
     
     // Get the function pointer (or index if this is a virtual function).
     if (MD->isVirtual()) {
-      uint64_t Index = CGM.GetVtableIndex(MD->getCanonicalDecl());
+      int64_t Index = CGM.getVtableInfo().getMethodVtableIndex(MD);
       
       Values[0] = llvm::ConstantInt::get(PtrDiffTy, Index + 1);
     } else {