Fast path for the regexp of bounded words.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 13a16541e628831658f27655425308064b1950db..216c12b29367dc66e85fc85b428c233bb50e3947 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -244,7 +244,8 @@ namespace internal {
   V(infinity_symbol, "Infinity")                                         \
   V(minus_infinity_symbol, "-Infinity")                                  \
   V(hidden_stack_trace_symbol, "v8::hidden_stack_trace")                 \
-  V(query_colon_symbol, "(?:)")
+  V(query_colon_symbol, "(?:)")                                          \
+  V(bounded_word_regexp_symbol, "\\b\\w+\\b")
 
 // Forward declarations.
 class GCTracer;