A64: Synchronize with r18764.

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index e2d222e5c674663095cb4b05ad29f564200f5da7..9dd3bc1b23a29117e88623781ef3189170cad1e2 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -220,7 +220,7 @@ DEFINE_bool(pretenuring, true, "allocate objects in old space")
 // TODO(hpayer): We will remove this flag as soon as we have pretenuring
 // support for specific allocation sites.
 DEFINE_bool(pretenuring_call_new, false, "pretenure call new")
-DEFINE_bool(allocation_site_pretenuring, false,
+DEFINE_bool(allocation_site_pretenuring, true,
             "pretenure with allocation sites")
 DEFINE_bool(trace_pretenuring, false,
             "trace pretenuring decisions of HAllocate instructions")
@@ -349,8 +349,6 @@ DEFINE_bool(omit_map_checks_for_leaf_maps, true,
             "do not emit check maps for constant values that have a leaf map, "
             "deoptimize the optimized code if the layout of the maps changes.")
 
-DEFINE_bool(new_string_add, true, "enable new string addition")
-
 // Profiler flags.
 DEFINE_int(frame_count, 1, "number of stack frames inspected by the profiler")
            // 0x1700 fits in the immediate field of an ARM instruction.
@@ -398,9 +396,7 @@ DEFINE_bool(enable_vldr_imm, false,
 // bootstrapper.cc
 DEFINE_string(expose_natives_as, NULL, "expose natives in global object")
 DEFINE_string(expose_debug_as, NULL, "expose debug in global object")
-#ifdef ADDRESS_SANITIZER
 DEFINE_bool(expose_free_buffer, false, "expose freeBuffer extension")
-#endif
 DEFINE_bool(expose_gc, false, "expose gc extension")
 DEFINE_string(expose_gc_as, NULL,
               "expose gc extension under the specified name")