reinstate patch which should not have been removed

lang/ocaml/Makefile

@@ -3,7 +3,7 @@ COMMENT =	   ML language with complete class-based objective system
 # XXX Don't even think of updating ocaml alone.
 # Do check that the ports that depend on it still work, or repair them.
 VERSION=		4.12.1
-REVISION=		1
+REVISION=		2
 
 PKGNAME =		ocaml-${VERSION:C/\+//}
 

lang/ocaml/patches/patch-configure_ac

@@ -0,0 +1,45 @@
+Index: configure.ac
+--- configure.ac.orig
++++ configure.ac
+@@ -735,6 +735,11 @@ AS_CASE([$CC,$host],
+ )
+ 
+ 
++# Respect LDFLAGS and CFLAGS
++common_cflags="$common_cflags $CFLAGS"
++oc_ldflags="$oc_ldflags $LDFLAGS"
++
++
+ ## Program to use to install files
+ AC_PROG_INSTALL
+ 
+@@ -867,10 +872,10 @@ AS_IF([test x"$enable_shared" != "xno"],
+     [[*-*-linux*|*-*-freebsd[3-9]*|*-*-freebsd[1-9][0-9]*\
+     |*-*-openbsd*|*-*-netbsd*|*-*-dragonfly*|*-*-gnu*|*-*-haiku*]],
+       [sharedlib_cflags="-fPIC"
++      oc_ldflags="$oc_ldflags -Wl,-E"
+        AS_CASE([$CC,$host],
+            [gcc*,powerpc-*-linux*], [mksharedlib="$CC -shared -mbss-plt"],
+-           [mksharedlib="$CC -shared"])
+-      oc_ldflags="$oc_ldflags -Wl,-E"
++           [mksharedlib="$CC -shared $oc_ldflags"])
+       rpath="-Wl,-rpath,"
+       mksharedlibrpath="-Wl,-rpath,"
+       natdynlinkopts="-Wl,-E"
+@@ -912,6 +917,7 @@ AS_IF([test x"$enable_shared" != "xno"],
+     [earm*-*-netbsd*], [natdynlink=true],
+     [aarch64-*-linux*], [natdynlink=true],
+     [aarch64-*-freebsd*], [natdynlink=true],
++    [aarch64-*-openbsd*], [natdynlink=true],
+     [riscv*-*-linux*], [natdynlink=true])])
+ 
+ # Try to work around the Skylake/Kaby Lake processor bug.
+@@ -1013,6 +1019,8 @@ AS_CASE([$host],
+     [arch=arm64; system=linux],
+   [aarch64-*-freebsd*],
+     [arch=arm64; system=freebsd],
++  [aarch64-*-openbsd*],
++    [arch=arm64; system=openbsd],
+   [x86_64-*-cygwin*],
+     [arch=amd64; system=cygwin],
+   [riscv64-*-linux*],