[coroutines] Add overloaded unary 'operator co_await'.

llvm-svn: 250991
diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
index cf5289a..93b80e5 100644
--- a/clang/lib/AST/StmtProfile.cpp
+++ b/clang/lib/AST/StmtProfile.cpp
@@ -854,6 +854,7 @@
   case OO_Arrow:
   case OO_Call:
   case OO_Conditional:
+  case OO_Coawait:
   case NUM_OVERLOADED_OPERATORS:
     llvm_unreachable("Invalid operator call kind");