Fix breakage on Windows, cannot redeclare loop variable i in the immediate scope of loop.  Rename variable to j.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@75365 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index 45825e1..3ffeb57 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -108,11 +108,11 @@
       const CXXBaseSpecifier *VBase = Bases[i];
       if (!VBase->isVirtual())
         continue;
-      int i;
-      for (i = 0; i < vbaseCount; ++i)
-        if (UniqueVbases[i]->getType() == VBase->getType())
+      int j;
+      for (j = 0; j < vbaseCount; ++j)
+        if (UniqueVbases[j]->getType() == VBase->getType())
           break;
-      if (i == vbaseCount) {
+      if (j == vbaseCount) {
         UniqueVbases.push_back(VBase);
         ++vbaseCount;
       }