tests: run tests for each supported personality

When strace supports more than one personality, run test suite
for each personality supported by the host system.

* bootstrap: Create tests-m32 and tests-mx32 subtrees from tests.
* configure.ac: Check for -m32 and -mx32 runtime support.
(AC_CONFIG_FILES): Add tests-m32/Makefile and tests-mx32/Makefile.
* Makefile.am [HAVE_M32_RUNTIME] (TESTS_M32): Define.
[HAVE_MX32_RUNTIME] (TESTS_MX32): Define.
(SUBDIRS): Add $(TESTS_M32) $(TESTS_MX32).
* .gitignore: Add /tests-m32 and /tests-mx32.
diff --git a/bootstrap b/bootstrap
index 91d1a8f..9624fec 100755
--- a/bootstrap
+++ b/bootstrap
@@ -1,3 +1,17 @@
-#!/bin/sh
+#!/bin/sh -eu
+
+for m in -m32 -mx32; do
+	mkdir tests$m ||
+		continue
+	sed "s/^AM_CFLAGS[[:space:]]*=.*/& $m/" \
+		tests/Makefile.am > tests$m/Makefile.am
+	for f in tests/*; do
+		[ "${f##*/}" != Makefile.am ] ||
+			continue
+		ln -s ../"$f" tests$m/
+	done
+done
+
 ./xlat/gen.sh
+
 exec autoreconf -f -i "$@"