[coroutines] Rename driver flag -fcoroutines to -fcoroutines-ts

Summary:
Also makes -fcoroutines_ts to be both a Driver and CC1 flag.

Patch mostly by EricWF.

Reviewers: rnk, cfe-commits, rsmith, EricWF

Subscribers: mehdi_amini

Differential Revision: https://reviews.llvm.org/D25130

llvm-svn: 283064
diff --git a/clang/test/SemaCXX/coroutines.cpp b/clang/test/SemaCXX/coroutines.cpp
index 92fdc79..17bf5d0 100644
--- a/clang/test/SemaCXX/coroutines.cpp
+++ b/clang/test/SemaCXX/coroutines.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++14 -fcoroutines -verify %s
+// RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -verify %s
 
 void no_coroutine_traits_bad_arg_await() {
   co_await a; // expected-error {{include <coroutine>}}