Name argument in forward declaration.

Unbreaks the build.
TBR: whesse@chromium.org
Review URL: http://codereview.chromium.org/5126002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5841 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/bignum-dtoa.cc

@@ -48,7 +48,7 @@ static int NormalizedExponent(uint64_t significand, int exponent) {
 
 // Forward declarations:
 // Returns an estimation of k such that 10^(k-1) <= v < 10^k.
-static int EstimatePower(int);
+static int EstimatePower(int exponent);
 // Computes v / 10^estimated_power exactly, as a ratio of two bignums, numerator
 // and denominator.
 static void InitialScaledStartValues(double v,