Add addrspacecast instruction.

Patch by Michele Scandale!

llvm-svn: 194760
diff --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
index 6698f83..35808a6 100644
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -365,7 +365,8 @@
         break;
       }
       V = GEP->getPointerOperand();
-    } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+    } else if (Operator::getOpcode(V) == Instruction::BitCast ||
+               Operator::getOpcode(V) == Instruction::AddrSpaceCast) {
       V = cast<Operator>(V)->getOperand(0);
     } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
       if (StripKind == PSK_ZeroIndices || GA->mayBeOverridden())