[Concepts] Deprecate -fconcepts-ts, enable Concepts under -std=c++2a
Now with concepts support merged and mostly complete, we do not need -fconcepts-ts
(which was also misleading as we were not implementing the TS) and can enable
concepts features under C++2a. A warning will be generated if users still attempt
to use -fconcepts-ts.
diff --git a/clang/test/Parser/cxx2a-concepts-requires-expr.cpp b/clang/test/Parser/cxx2a-concepts-requires-expr.cpp
index a53189c..6b4a5d6 100644
--- a/clang/test/Parser/cxx2a-concepts-requires-expr.cpp
+++ b/clang/test/Parser/cxx2a-concepts-requires-expr.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++2a -fconcepts-ts -x c++ %s -verify
+// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify
bool r1 = requires () {};
// expected-error@-1 {{a requires expression must contain at least one requirement}}