Reintroduce duplicate identifier detection in preparser.

src/conversions.cc

Index: src/conversions.cc
diff --git a/src/conversions.cc b/src/conversions.cc
index c34fe519c42f94c6652650c7acbd2c3d74e70c5c..b634ba799c582fb0cff966adaa9819ec59f08c56 100644
--- a/src/conversions.cc
+++ b/src/conversions.cc
@@ -26,6 +26,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <stdarg.h>
+#include <math.h>
 #include <limits.h>
 
 #include "conversions-inl.h"
@@ -38,7 +39,6 @@ namespace v8 {
 namespace internal {
 
 
-
 double StringToDouble(UnicodeCache* unicode_cache,
                       const char* str, int flags, double empty_string_val) {
   const char* end = str + StrLength(str);
@@ -390,7 +390,7 @@ char* DoubleToRadixCString(double value, int radix) {
   int integer_pos = kBufferSize - 2;
   do {
     integer_buffer[integer_pos--] =
-        chars[static_cast<int>(modulo(integer_part, radix))];
+        chars[static_cast<int>(fmod(integer_part, radix))];
     integer_part /= radix;
   } while (integer_part >= 1.0);
   // Sanity check.