gdb: Fix an ODR warning with byacc with GDB_YY_REMAP

With byacc, we get an ODR warning with YYSTACKDATA between ada-exp.c.tmp
and c-exp.c.tmp. Just include it in the list of symbols we rename.

PR gdb/30839

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30839


Approved-By: Tom de Vries <tdevries@suse.de>
Copyright-paperwork-exempt: yes