In python shlib probe, cater for OpenBSD, which omits the .so symlink.

Most Unix-oid platforms provide a symlink "libfoo.so" -> "libfoo.so.n.n"
to allow the linker to resolve a reference "-lfoo" to a version-numbered
shared library.  OpenBSD has apparently hacked ld(1) to do this internally,
because there are no such symlinks to be found in their library
directories.  Tweak the new code in PGAC_CHECK_PYTHON_EMBED_SETUP to cope.
Per buildfarm member curculio.

config/python.m4

@@ -85,6 +85,7 @@ ldlibrary=`echo "${python_ldlibrary}" | sed -e 's/\.so$//' -e 's/\.dll$//' -e 's
 if test -e "${python_libdir}/${python_ldlibrary}" -a x"${python_ldlibrary}" != x"${ldlibrary}"
 then
 	ldlibrary=`echo "${ldlibrary}" | sed "s/^lib//"`
+	found_shlib=1
 else
 	# Otherwise, guess the base name of the shlib.
 	# LDVERSION was added in Python 3.2, before that use $python_version.
@@ -98,6 +99,7 @@ else
 	found_shlib=0
 	for d in "${python_libdir}" "${python_configdir}" /usr/lib64 /usr/lib
 	do
+		# We don't know the platform DLSUFFIX here, so check 'em all.
 		for e in .so .dll .dylib .sl; do
 			if test -e "$d/lib${ldlibrary}$e"; then
 				python_libdir="$d"
@@ -106,12 +108,28 @@ else
 			fi
 		done
 	done
+	# Some platforms (OpenBSD) require us to accept a bare versioned shlib
+	# (".so.n.n") as well. However, check this only after failing to find
+	# ".so" anywhere, because yet other platforms (Debian) put the .so
+	# symlink in a different directory from the underlying versioned shlib.
 	if test "$found_shlib" != 1; then
-		AC_MSG_ERROR([could not find shared library for Python
+		for d in "${python_libdir}" "${python_configdir}" /usr/lib64 /usr/lib
+		do
+			for f in "$d/lib${ldlibrary}.so."* ; do
+				if test -e "$f"; then
+					python_libdir="$d"
+					found_shlib=1
+					break 2
+				fi
+			done
+		done
+	fi
+fi
+if test "$found_shlib" != 1; then
+	AC_MSG_ERROR([could not find shared library for Python
 You might have to rebuild your Python installation.  Refer to the
 documentation for details.  Use --without-python to disable building
 PL/Python.])
-	fi
 fi
 python_libspec="-L${python_libdir} -l${ldlibrary}"
 

configure

@@ -7628,6 +7628,7 @@ ldlibrary=`echo "${python_ldlibrary}" | sed -e 's/\.so$//' -e 's/\.dll$//' -e 's
 if test -e "${python_libdir}/${python_ldlibrary}" -a x"${python_ldlibrary}" != x"${ldlibrary}"
 then
 	ldlibrary=`echo "${ldlibrary}" | sed "s/^lib//"`
+	found_shlib=1
 else
 	# Otherwise, guess the base name of the shlib.
 	# LDVERSION was added in Python 3.2, before that use $python_version.
@@ -7641,6 +7642,7 @@ else
 	found_shlib=0
 	for d in "${python_libdir}" "${python_configdir}" /usr/lib64 /usr/lib
 	do
+		# We don't know the platform DLSUFFIX here, so check 'em all.
 		for e in .so .dll .dylib .sl; do
 			if test -e "$d/lib${ldlibrary}$e"; then
 				python_libdir="$d"
@@ -7649,12 +7651,28 @@ else
 			fi
 		done
 	done
+	# Some platforms (OpenBSD) require us to accept a bare versioned shlib
+	# (".so.n.n") as well. However, check this only after failing to find
+	# ".so" anywhere, because yet other platforms (Debian) put the .so
+	# symlink in a different directory from the underlying versioned shlib.
 	if test "$found_shlib" != 1; then
-		as_fn_error $? "could not find shared library for Python
+		for d in "${python_libdir}" "${python_configdir}" /usr/lib64 /usr/lib
+		do
+			for f in "$d/lib${ldlibrary}.so."* ; do
+				if test -e "$f"; then
+					python_libdir="$d"
+					found_shlib=1
+					break 2
+				fi
+			done
+		done
+	fi
+fi
+if test "$found_shlib" != 1; then
+	as_fn_error $? "could not find shared library for Python
 You might have to rebuild your Python installation.  Refer to the
 documentation for details.  Use --without-python to disable building
 PL/Python." "$LINENO" 5
-	fi
 fi
 python_libspec="-L${python_libdir} -l${ldlibrary}"