Revert r4591

src/fast-dtoa.h

Index: src/fast-dtoa.h
===================================================================
--- src/fast-dtoa.h	(revision 4591)
+++ src/fast-dtoa.h	(working copy)
@@ -36,7 +36,7 @@
 static const int kFastDtoaMaximalLength = 17;
 
 // Provides a decimal representation of v.
-// v must be a strictly positive finite double.
+// v must not be (positive or negative) zero and it must not be Infinity or NaN.
 // Returns true if it succeeds, otherwise the result can not be trusted.
 // There will be *length digits inside the buffer followed by a null terminator.
 // If the function returns true then
@@ -50,6 +50,7 @@
 //   otherwise.
 bool FastDtoa(double d,
               Vector<char> buffer,
+              int* sign,
               int* length,
               int* point);