Stage ES6 template literals

BUG=v8:3230
LOG=Y
R=dslomov@chromium.org, rossberg@chromium.org

Review URL: https://codereview.chromium.org/780603003

Cr-Commit-Position: refs/heads/master@{#25659}

src/flag-definitions.h

@@ -168,7 +168,6 @@ DEFINE_IMPLICATION(es_staging, harmony)
   V(harmony_regexps, "harmony regular expression extensions")             \
   V(harmony_arrow_functions, "harmony arrow functions")                   \
   V(harmony_proxies, "harmony proxies")                                   \
-  V(harmony_templates, "harmony template literals")                       \
   V(harmony_sloppy, "harmony features in sloppy mode")                    \
   V(harmony_unicode, "harmony unicode escapes")
 
@@ -178,7 +177,8 @@ DEFINE_IMPLICATION(es_staging, harmony)
     "harmony classes (implies block scoping & object literal extension)") \
   V(harmony_object_literals, "harmony object literal extensions")         \
   V(harmony_tostring, "harmony toString")                                 \
-  V(harmony_scoping, "harmony block scoping")
+  V(harmony_scoping, "harmony block scoping")                             \
+  V(harmony_templates, "harmony template literals")
 
 // Features that are shipping (turned on by default, but internal flag remains).
 #define HARMONY_SHIPPING(V)                               \