Fix build on arm64

- Update SpiderMonkey config.guess
- Include patch for SpiderMonkey Mozilla bug 638056

3rdp/build/GNUmakefile

@@ -71,6 +71,8 @@ $(JSLIB_BUILD): $(3RDP_ROOT)/dist/libmozjs.tgz $(3RDP_ROOT)/build/js_src_jsnativ
 	$(QUIET)patch -b -p0 -d $(JS_SRC) < js-volatile-outside-functions.patch
 	$(QUIET)patch -b -p0 -d $(JS_SRC) < js-Wno-misleading-indentation.patch
 	$(QUIET)patch -b -p0 -d $(JS_SRC) < js-allow-python3.patch
+	$(QUIET)patch -b -p0 -d $(JS_SRC) < js-config.guess.patch
+	$(QUIET)patch -b -p0 -d $(JS_SRC) < js-makefile.patch
 	-$(QUIET)cd $(JS_SRC)/js-1.8.5/js/src && autoconf-2.13
 	$(QUIET)cd $(JS_SRC)/js-1.8.5/js/src && env $(JS_CONFIGURE_ENV) ./configure $(JS_CONFIGURE_ARGS)
 	$(QUIET)$(MAKE) -C $(JS_SRC)/js-1.8.5/js/src

3rdp/build/js-makefile.patch

+--- js-1.8.5/js/src/Makefile.in
++++ js-1.8.5/js/src/Makefile.in
+@@ -382,7 +382,7 @@
+ # END enclude sources for V8 dtoa
+ #############################################
+ 
+-ifeq (,$(filter-out powerpc sparc,$(TARGET_CPU)))
++ifeq (,$(filter arm %86 x86_64,$(TARGET_CPU)))
+ 
+ VPATH +=	$(srcdir)/assembler \
+ 		$(srcdir)/assembler/wtf \