Add support for Windows on ARM and ARM64 (#76)

diff --git a/double-conversion/utils.h b/double-conversion/utils.h
index 28bb694..98a2a11 100644
--- a/double-conversion/utils.h
+++ b/double-conversion/utils.h
@@ -68,7 +68,7 @@
 // disabled.)
 // On Linux,x86 89255e-22 != Div_double(89255.0/1e22)
 #if defined(_M_X64) || defined(__x86_64__) || \
-    defined(__ARMEL__) || defined(__avr32__) || \
+    defined(__ARMEL__) || defined(__avr32__) || defined(_M_ARM) || defined(_M_ARM64) || \
     defined(__hppa__) || defined(__ia64__) || \
     defined(__mips__) || \
     defined(__powerpc__) || defined(__ppc__) || defined(__ppc64__) || \