Switch assert(0/false) llvm_unreachable.

llvm-svn: 140367
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 5b44841..166e165 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -3400,7 +3400,7 @@
     break;
     
   default:
-    assert(false && "Unknown type specifier kind in CodeCompleteTag");
+    llvm_unreachable("Unknown type specifier kind in CodeCompleteTag");
     return;
   }