Fix a test with malformed IR.  Not sure why this didn't fail before.

llvm-svn: 109422
diff --git a/llvm/test/Transforms/JumpThreading/crash.ll b/llvm/test/Transforms/JumpThreading/crash.ll
index f0fc61e..4fe94e5 100644
--- a/llvm/test/Transforms/JumpThreading/crash.ll
+++ b/llvm/test/Transforms/JumpThreading/crash.ll
@@ -216,6 +216,9 @@
 
 ; PR5698
 define void @test7(i32 %x) {
+entry:
+  br label %tailrecurse
+
 tailrecurse:
   switch i32 %x, label %return [
     i32 2, label %bb2