fdsan: expose the address of the table to the platform.

Let the debuggerd handler get the address of the fdsan table so that
crash_dump can parse it and print it out in tombstones.

Test: debuggerd `pidof adbd`
Change-Id: I2297200cae52d0ff24479dba55d1ab4938583501
diff --git a/libc/libc.arm.map b/libc/libc.arm.map
index 23ee3f3..6d39812 100644
--- a/libc/libc.arm.map
+++ b/libc/libc.arm.map
@@ -1661,6 +1661,7 @@
     __system_property_area_init;
     __system_property_set_filename;
     __system_property_update;
+    android_fdsan_get_fd_table;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;
     android_net_res_stats_get_usable_servers;