Allow more runtime functions to accept Int32s instead of Smis.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index f0c1d95f88275bc3b5a6af003d149d27ffa51c12..2a1df1e29d01620c4384e527356cd726fbb2a421 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -7169,10 +7169,10 @@ RUNTIME_FUNCTION(Runtime_StringBuilderConcat) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
-  if (!args[1]->IsSmi()) {
+  int32_t array_length;
+  if (!args[1]->ToInt32(&array_length)) {
     THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());
   }
-  CONVERT_SMI_ARG_CHECKED(array_length, 1);
   CONVERT_ARG_HANDLE_CHECKED(String, special, 2);
 
   size_t actual_array_length = 0;
@@ -7243,10 +7243,10 @@ RUNTIME_FUNCTION(Runtime_StringBuilderJoin) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
-  if (!args[1]->IsSmi()) {
+  int32_t array_length;
+  if (!args[1]->ToInt32(&array_length)) {
     THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());
   }
-  CONVERT_SMI_ARG_CHECKED(array_length, 1);
   CONVERT_ARG_HANDLE_CHECKED(String, separator, 2);
   RUNTIME_ASSERT(array->HasFastObjectElements());
   RUNTIME_ASSERT(array_length >= 0);