Switch assert(0/false) llvm_unreachable.

llvm-svn: 140367
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index f83f709..4d92e31 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4993,7 +4993,7 @@
   }
   }
 
-  assert(0 && "Unhandled template name kind!");
+  llvm_unreachable("Unhandled template name kind!");
   return TemplateName();
 }
 
@@ -5033,7 +5033,7 @@
   }
   }
 
-  assert(0 && "Unhandled template argument kind!");
+  llvm_unreachable("Unhandled template argument kind!");
   return TemplateArgument();
 }