Switch assert(0/false) llvm_unreachable.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140367 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index cda4d92..052ef3b 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -548,7 +548,7 @@
   unsigned BuiltinID = FDecl->getBuiltinID();
   unsigned BuiltinIndex, NumFixed = 1;
   switch (BuiltinID) {
-  default: assert(0 && "Unknown overloaded atomic builtin!");
+  default: llvm_unreachable("Unknown overloaded atomic builtin!");
   case Builtin::BI__sync_fetch_and_add: BuiltinIndex = 0; break;
   case Builtin::BI__sync_fetch_and_sub: BuiltinIndex = 1; break;
   case Builtin::BI__sync_fetch_and_or:  BuiltinIndex = 2; break;