[builtins] Remove STRING_ADD_LEFT and STRING_ADD_RIGHT builtins.

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index d56224046a01bebed9b41305b3afb781207d0d08..dd5e1add8bc9bb72315a47e8c4be4b9b57ff476e 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -90,19 +90,17 @@ enum BindingFlags {
   V(TO_STRING_FUN_INDEX, JSFunction, to_string_fun)
 
 
-#define NATIVE_CONTEXT_JS_BUILTINS(V)                                   \
-  V(APPLY_PREPARE_BUILTIN_INDEX, JSFunction, apply_prepare_builtin)     \
-  V(COMPARE_BUILTIN_INDEX, JSFunction, compare_builtin)                 \
-  V(COMPARE_STRONG_BUILTIN_INDEX, JSFunction, compare_strong_builtin)   \
-  V(CONCAT_ITERABLE_TO_ARRAY_BUILTIN_INDEX, JSFunction,                 \
-    concat_iterable_to_array_builtin)                                   \
-  V(EQUALS_BUILTIN_INDEX, JSFunction, equals_builtin)                   \
-  V(REFLECT_APPLY_PREPARE_BUILTIN_INDEX, JSFunction,                    \
-    reflect_apply_prepare_builtin)                                      \
-  V(REFLECT_CONSTRUCT_PREPARE_BUILTIN_INDEX, JSFunction,                \
-    reflect_construct_prepare_builtin)                                  \
-  V(STRING_ADD_LEFT_BUILTIN_INDEX, JSFunction, string_add_left_builtin) \
-  V(STRING_ADD_RIGHT_BUILTIN_INDEX, JSFunction, string_add_right_builtin)
+#define NATIVE_CONTEXT_JS_BUILTINS(V)                                 \
+  V(APPLY_PREPARE_BUILTIN_INDEX, JSFunction, apply_prepare_builtin)   \
+  V(COMPARE_BUILTIN_INDEX, JSFunction, compare_builtin)               \
+  V(COMPARE_STRONG_BUILTIN_INDEX, JSFunction, compare_strong_builtin) \
+  V(CONCAT_ITERABLE_TO_ARRAY_BUILTIN_INDEX, JSFunction,               \
+    concat_iterable_to_array_builtin)                                 \
+  V(EQUALS_BUILTIN_INDEX, JSFunction, equals_builtin)                 \
+  V(REFLECT_APPLY_PREPARE_BUILTIN_INDEX, JSFunction,                  \
+    reflect_apply_prepare_builtin)                                    \
+  V(REFLECT_CONSTRUCT_PREPARE_BUILTIN_INDEX, JSFunction,              \
+    reflect_construct_prepare_builtin)
 
 
 #define NATIVE_CONTEXT_IMPORTED_FIELDS(V)                                     \