Add OS/2 supports

Change-Id: I792d5236451905eb20a8ebe444ef5b2274e4f7a4
diff --git a/configure b/configure
index 7ecd72e..4ac97b1 100755
--- a/configure
+++ b/configure
@@ -109,6 +109,7 @@
 all_platforms="${all_platforms} x86-darwin10-gcc"
 all_platforms="${all_platforms} x86-linux-gcc"
 all_platforms="${all_platforms} x86-linux-icc"
+all_platforms="${all_platforms} x86-os2-gcc"
 all_platforms="${all_platforms} x86-solaris-gcc"
 all_platforms="${all_platforms} x86-win32-gcc"
 all_platforms="${all_platforms} x86-win32-vs7"