Update arch_test.c properly for arm-linux, and add an entry to
platform_test.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11007 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/tests/arch_test.c b/tests/arch_test.c
index 469c848..9db75e5 100644
--- a/tests/arch_test.c
+++ b/tests/arch_test.c
@@ -27,6 +27,7 @@
    "amd64",
    "ppc32",
    "ppc64",
+   "arm",
    NULL
 };