c_src/double-conversion/utils.h: Add support for AArch64

AArch64 uses 64bit doubles so handle similarly to other architectures.

c_src/double-conversion/utils.h

@@ -58,7 +58,7 @@
     defined(__mips__) || defined(__powerpc__) || \
     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
     defined(__SH4__) || defined(__alpha__) || \
-    defined(_MIPS_ARCH_MIPS32R2)
+    defined(_MIPS_ARCH_MIPS32R2) || defined(__aarch64__)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
 #elif defined(_M_IX86) || defined(__i386__) || defined(__i386)
 #if defined(_WIN32)