Remove dead strings from heap.h

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 94fbf46e7f4e14c10451571477ae0347e47ba090..4dfa076ebd7745c14e953cbf0deb3bd396eb5c5a 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -199,7 +199,6 @@ namespace internal {
   V(Array_string, "Array")                                               \
   V(Object_string, "Object")                                             \
   V(proto_string, "__proto__")                                           \
-  V(StringImpl_string, "StringImpl")                                     \
   V(arguments_string, "arguments")                                       \
   V(Arguments_string, "Arguments")                                       \
   V(call_string, "call")                                                 \
@@ -209,12 +208,10 @@ namespace internal {
   V(Boolean_string, "Boolean")                                           \
   V(callee_string, "callee")                                             \
   V(constructor_string, "constructor")                                   \
-  V(code_string, ".code")                                                \
   V(result_string, ".result")                                            \
   V(dot_for_string, ".for.")                                             \
-  V(catch_var_string, ".catch-var")                                      \
-  V(empty_string, "")                                                    \
   V(eval_string, "eval")                                                 \
+  V(empty_string, "")                                                    \
   V(function_string, "function")                                         \
   V(length_string, "length")                                             \
   V(module_string, "module")                                             \
@@ -233,12 +230,10 @@ namespace internal {
   V(index_string, "index")                                               \
   V(last_index_string, "lastIndex")                                      \
   V(object_string, "object")                                             \
-  V(payload_string, "payload")                                           \
   V(literals_string, "literals")                                         \
   V(prototype_string, "prototype")                                       \
   V(string_string, "string")                                             \
   V(String_string, "String")                                             \
-  V(unknown_field_string, "unknownField")                                \
   V(symbol_string, "symbol")                                             \
   V(Symbol_string, "Symbol")                                             \
   V(Date_string, "Date")                                                 \
@@ -257,7 +252,6 @@ namespace internal {
     "KeyedStoreElementMonomorphic")                                      \
   V(stack_overflow_string, "kStackOverflowBoilerplate")                  \
   V(illegal_access_string, "illegal access")                             \
-  V(out_of_memory_string, "out-of-memory")                               \
   V(illegal_execution_state_string, "illegal execution state")           \
   V(get_string, "get")                                                   \
   V(set_string, "set")                                                   \
@@ -266,8 +260,6 @@ namespace internal {
   V(length_field_string, "%length")                                      \
   V(cell_value_string, "%cell_value")                                    \
   V(function_class_string, "Function")                                   \
-  V(properties_field_symbol, "%properties")                              \
-  V(payload_field_symbol, "%payload")                                    \
   V(illegal_argument_string, "illegal argument")                         \
   V(MakeReferenceError_string, "MakeReferenceError")                     \
   V(MakeSyntaxError_string, "MakeSyntaxError")                           \
@@ -281,7 +273,6 @@ namespace internal {
   V(illegal_continue_string, "illegal_continue")                         \
   V(unknown_label_string, "unknown_label")                               \
   V(redeclaration_string, "redeclaration")                               \
-  V(failure_string, "<failure>")                                         \
   V(space_string, " ")                                                   \
   V(exec_string, "exec")                                                 \
   V(zero_string, "0")                                                    \