Prefix `next' iterator operation with `llvm::'.

Fixes potential ambiguity problems on VS 2010.

Patch by nobled!

llvm-svn: 110029
diff --git a/llvm/unittests/VMCore/InstructionsTest.cpp b/llvm/unittests/VMCore/InstructionsTest.cpp
index c1baa74..c9fe2a1 100644
--- a/llvm/unittests/VMCore/InstructionsTest.cpp
+++ b/llvm/unittests/VMCore/InstructionsTest.cpp
@@ -59,9 +59,9 @@
   EXPECT_EQ(b0->getNumOperands(), 1U);
 
   EXPECT_NE(b0->op_begin(), b0->op_end());
-  EXPECT_EQ(next(b0->op_begin()), b0->op_end());
+  EXPECT_EQ(llvm::next(b0->op_begin()), b0->op_end());
 
-  EXPECT_EQ(next(b0->op_begin()), b0->op_end());
+  EXPECT_EQ(llvm::next(b0->op_begin()), b0->op_end());
 
   const IntegerType* Int1 = IntegerType::get(C, 1);
   Constant* One = ConstantInt::get(Int1, 1, true);