some warnings

[mrdudz]

just for info, i noticed these when compiling with clang

In file included from vice/vice-emu/trunk/vice/src/sid/residfp.cc:63:
In file included from vice/vice-emu/trunk/vice/src/lib/libresidfp/src/SID.h:36:
vice/vice-emu/trunk/vice/src/lib/libresidfp/src/State.h:46:1: warning: 'State' defined as a struct here but
      previously declared as a class; this is valid, but may result in linker errors under the Microsoft C++ ABI [-Wmismatched-tags]
   46 | struct State
      | ^
vice/vice-emu/trunk/vice/src/lib/libresidfp/src/ExternalFilter.h:88:12: note: did you mean struct here?
   88 |     friend class State;
      |            ^~~~~
      |            struct
In file included from vice/vice-emu/trunk/vice/src/sid/residfp.cc:63:
vice/vice-emu/trunk/vice/src/lib/libresidfp/src/SID.h:65:12: warning: class 'State' was previously declared as a
      struct; this is valid, but may result in linker errors under the Microsoft C++ ABI [-Wmismatched-tags]
   65 |     friend class State;
      |            ^
vice/vice-emu/trunk/vice/src/lib/libresidfp/src/State.h:46:8: note: previous use is here
   46 | struct State
      |        ^
vice/vice-emu/trunk/vice/src/lib/libresidfp/src/SID.h:65:12: note: did you mean struct here?
   65 |     friend class State;
      |            ^~~~~
      |            struct
2 warnings generated.

[drfiemost]

Thanks, should be fixed with #46

[mrdudz]

I'll provide more... i'm doing testruns with address- and UB sanitizer in VICE atm, got some warnings about libresidfp as well...