Sync with upstream OpenBSD.

Test: treehugger
Change-Id: I1fc649ba5d79a3d95242c6b2240dbb05c85d30e9
diff --git a/libc/upstream-openbsd/android/include/openbsd-compat.h b/libc/upstream-openbsd/android/include/openbsd-compat.h
index 8206269..2fc5046 100644
--- a/libc/upstream-openbsd/android/include/openbsd-compat.h
+++ b/libc/upstream-openbsd/android/include/openbsd-compat.h
@@ -72,3 +72,7 @@
 
 __LIBC_HIDDEN__ extern char* __findenv(const char*, int, int*);
 __LIBC_HIDDEN__ extern char* _mktemp(char*);
+
+// Only OpenBSD has this at the moment, and we're more likely to just say
+// "malloc is always calloc", so we don't expose this as libc API.
+__LIBC_HIDDEN__ void* recallocarray(void*, size_t, size_t, size_t);