issue #2 use new __has_builtin macro

Makefile

@@ -181,7 +181,7 @@ $(SRCDIR)/configure : $(PROJECT_TEMP_DIR)/$(TARBALL)
 	mkdir -p $(SRCROOT)
 	tar -C $(SRCROOT) -xmf $(PROJECT_TEMP_DIR)/$(TARBALL)
 	if [ -d patches/$(VERSION) ] ; then \
-		for p in patches/$(VERSION)/* ; do \
+		for p in patches/$(VERSION)/*.patch ; do \
 			if [ -f $$p ] ; then \
 				patch -d $(SRCDIR) -p1 < $$p ; \
 			fi ; \

patches/7.55.1/connect_c_ios8.patch

@@ -1,15 +1,16 @@
---- curl-7.55.1/lib/connect.c	2017-09-26 18:31:48.000000000 -0700
-+++ curl-7.55.1.patched/lib/connect.c	2017-09-26 18:35:36.000000000 -0700
-@@ -1066,9 +1066,12 @@
+--- curl-7.55.1/lib/connect.c	2017-08-12 06:28:13.000000000 -0700
++++ curl-7.55.1.patched/lib/connect.c	2017-09-26 21:12:11.000000000 -0700
+@@ -1066,9 +1066,13 @@
        endpoints.sae_dstaddr = &addr.sa_addr;
        endpoints.sae_dstaddrlen = addr.addrlen;
 
-+#pragma GCC diagnostic push
-+#pragma GCC diagnostic ignored "-Wpartial-availability"
++#if __has_builtin(connectx)
        rc = connectx(sockfd, &endpoints, SAE_ASSOCID_ANY,
                      CONNECT_RESUME_ON_READ_WRITE | CONNECT_DATA_IDEMPOTENT,
                      NULL, 0, NULL, NULL);
-+#pragma GCC diagnostic pop
++#else
++      rc = connect(sockfd, &addr.sa_addr, addr.addrlen);
++#endif
  #elif defined(MSG_FASTOPEN) /* Linux */
        if(conn->given->flags & PROTOPT_SSL)
          rc = connect(sockfd, &addr.sa_addr, addr.addrlen);