Update upstream OpenBSD gdtoa.

Also add a test for the bug that this fixes.

Bug: http://b/152588929
Test: treehugger
Change-Id: I58055b3ebaef457721bb4f5d8a8710025122b2e7
diff --git a/libc/upstream-openbsd/android/include/openbsd-compat.h b/libc/upstream-openbsd/android/include/openbsd-compat.h
index 878f71c..8206269 100644
--- a/libc/upstream-openbsd/android/include/openbsd-compat.h
+++ b/libc/upstream-openbsd/android/include/openbsd-compat.h
@@ -38,6 +38,8 @@
 /* Ignore all __warn_references in OpenBSD. */
 #define __warn_references(sym,msg)
 
+#define PROTO_NORMAL(x)
+
 /* OpenBSD's <ctype.h> uses these names, which conflicted with stlport.
  * Additionally, we changed the numeric/digit type from N to D for libcxx.
  */