Index: head/lang/spidermonkey170/files/patch-utils.h
===================================================================
--- head/lang/spidermonkey170/files/patch-utils.h
+++ head/lang/spidermonkey170/files/patch-utils.h
@@ -0,0 +1,12 @@
+--- ../../mfbt/double-conversion/utils.h.orig	2016-01-04 09:48:39.700168000 +0000
++++ ../../mfbt/double-conversion/utils.h	2016-01-04 09:49:18.136290000 +0000
+@@ -58,7 +58,8 @@
+     defined(__mips__) || defined(__powerpc__) || \
+     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
+     defined(__SH4__) || defined(__alpha__) || \
+-    defined(_MIPS_ARCH_MIPS32R2)
++    defined(_MIPS_ARCH_MIPS32R2) || \
++    defined(__AARCH64EL__)
+ #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
+ #elif defined(_M_IX86) || defined(__i386__) || defined(__i386)
+ #if defined(_WIN32)
Index: head/lang/spidermonkey24/files/patch-utils.h
===================================================================
--- head/lang/spidermonkey24/files/patch-utils.h
+++ head/lang/spidermonkey24/files/patch-utils.h
@@ -0,0 +1,12 @@
+--- ../../mfbt/double-conversion/utils.h.orig	2016-01-04 09:48:39.700168000 +0000
++++ ../../mfbt/double-conversion/utils.h	2016-01-04 09:49:18.136290000 +0000
+@@ -58,7 +58,8 @@
+     defined(__mips__) || defined(__powerpc__) || \
+     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
+     defined(__SH4__) || defined(__alpha__) || \
+-    defined(_MIPS_ARCH_MIPS32R2)
++    defined(_MIPS_ARCH_MIPS32R2) || \
++    defined(__AARCH64EL__)
+ #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
+ #elif defined(_M_IX86) || defined(__i386__) || defined(__i386)
+ #if defined(_WIN32)