Bug 1481505 - add aarch64 bits to DEFINES and DSO_LDOPTS; r=dmajor

Not having _ARM64_ in DEFINES makes any number of things go wrong.

js/src/old-configure.in

@@ -852,6 +852,12 @@ case "$target" in
         fi
         AC_DEFINE(_AMD64_)
         ;;
+    aarch64-*)
+        if test -n "$_WIN32_MSVC"; then
+            DSO_LDOPTS="$DSO_LDOPTS -MACHINE:ARM64"
+        fi
+        AC_DEFINE(_ARM64_)
+        ;;
     *)
     	AC_DEFINE(_CPU_ARCH_NOT_DEFINED)
 	;;

old-configure.in

@@ -1102,6 +1102,12 @@ case "$target" in
         fi
         AC_DEFINE(_AMD64_)
         ;;
+    aarch64-*)
+        if test -n "$_WIN32_MSVC"; then
+            DSO_LDOPTS="$DSO_LDOPTS -MACHINE:ARM64"
+        fi
+        AC_DEFINE(_ARM64_)
+        ;;
     *)
         AC_DEFINE(_CPU_ARCH_NOT_DEFINED)
         ;;