[turbofan] Rename --context-specialization to --function-context-specialization.

test/mjsunit/regress/regress-osr-context.js

Index: test/mjsunit/regress/regress-osr-context.js
diff --git a/test/mjsunit/regress/regress-osr-context.js b/test/mjsunit/regress/regress-osr-context.js
index 8ceb79119ac72f8d06ad841ab7181b9ac902180b..a73954156ce94e09d59aff93aadf76c898bda98f 100644
--- a/test/mjsunit/regress/regress-osr-context.js
+++ b/test/mjsunit/regress/regress-osr-context.js
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --context-specialization --turbo-filter=f
+// Flags: --allow-natives-syntax --function-context-specialization
+// Flags: --turbo-filter=f
 
 (function() {
   "use strict";