[runtime] Simplify TO_INT32/TO_UINT32 abstract operations.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 0adbc8fd1a3847630c1a9c804b2cced3be3898b1..b364d223c925dce02ac6920ebc40a1229ce2e863 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1717,8 +1717,6 @@ void Genesis::InstallNativeFunctions() {
   INSTALL_NATIVE(JSFunction, "$toString", to_string_fun);
   INSTALL_NATIVE(JSFunction, "$toDetailString", to_detail_string_fun);
   INSTALL_NATIVE(JSFunction, "$toInteger", to_integer_fun);
-  INSTALL_NATIVE(JSFunction, "$toUint32", to_uint32_fun);
-  INSTALL_NATIVE(JSFunction, "$toInt32", to_int32_fun);
   INSTALL_NATIVE(JSFunction, "$toLength", to_length_fun);
 
   INSTALL_NATIVE(JSFunction, "$globalEval", global_eval_fun);