fix another libgcc blocker

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59026 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Alpha/AlphaISelLowering.cpp b/lib/Target/Alpha/AlphaISelLowering.cpp
index 7878830..1872b42 100644
--- a/lib/Target/Alpha/AlphaISelLowering.cpp
+++ b/lib/Target/Alpha/AlphaISelLowering.cpp
@@ -97,6 +97,7 @@
   setOperationAction(ISD::SUBE     , MVT::i64, Expand);
 
   setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
+  setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand);
 
 
   // We don't support sin/cos/sqrt/pow