suppress gcc3.4.6's <no value returned> warnings

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51372 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 91c745e..7601aeb 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -602,6 +602,7 @@
   if (Ty == Type::DoubleTy)
     return ConstantFP::get(APFloat(V));
   assert(0 && "Can only constant fold float/double");
+  return 0; // dummy return to suppress warning
 }
 
 static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
@@ -619,6 +620,7 @@
   if (Ty == Type::DoubleTy)
     return ConstantFP::get(APFloat(V));
   assert(0 && "Can only constant fold float/double");
+  return 0; // dummy return to suppress warning
 }
 
 /// ConstantFoldCall - Attempt to constant fold a call to the specified function