Convert assert(0) to llvm_unreachable

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149967 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index eb2e19d..f715f6f 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -706,9 +706,8 @@
   if (I != getBasicBlockAddressMap(locked).end()) {
     return I->second;
   } else {
-    assert(0 && "JIT does not have BB address for address-of-label, was"
-           " it eliminated by optimizer?");
-    return 0;
+    llvm_unreachable("JIT does not have BB address for address-of-label, was"
+                     " it eliminated by optimizer?");
   }
 }