[Bug plugins/108634] [13 regression] 'undefined symbol: tree_code_type' when building kernel GCC plugins since r13-5431-gb0241ce6e37031

[arsen at aarsen dot me]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108634

--- Comment #1 from Arsen Arsenović <arsen at aarsen dot me> ---
The kernel's using wrong C(XX)FLAGS to compile the plugin.  IMO, the best
solution would be to dump $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) into a makefile
that gets installed, so that plugins can use that