$OpenBSD: patch-libffi_ghc_mk,v 1.6 2017/11/07 02:58:34 kili Exp $

Unbreak the build on OpenBSD/amd64: undefined references to
'ffi_call_unix64', 'ffi_closure_unix64'

gcc supports @unwind sections while ld (binutils 2.15) does not

--- libffi/ghc.mk.orig	Mon May 16 19:08:53 2016
+++ libffi/ghc.mk	Wed Nov  2 11:07:58 2016
@@ -96,6 +96,7 @@ $(libffi_STAMP_CONFIGURE): $(TOUCH_DEP)
 	    RANLIB=$(REAL_RANLIB_CMD) \
         CFLAGS="$(SRC_CC_OPTS) $(CONF_CC_OPTS_STAGE1) -w" \
         LDFLAGS="$(SRC_LD_OPTS) -w" \
+        libffi_cv_as_x86_64_unwind_section_type=no \
         "$(SHELL)" ./configure \
 	          --prefix=$(TOP)/libffi/build/inst \
 	          --libdir=$(TOP)/libffi/build/inst/lib \
