Filter out `gcc2_compiled.` and family

[AngheloAlf]

Some compilers may emit section-relative relocations instead of symbol-relative ones, meaning objdiff's symbol resolution may end up picking up a compiler generated symbol like gcc2_compiled. or __gnu_compiled_c. Ideally this kind of symbol would be filtered out or be low priority.

This is how they are listed by readelf:

     3: 00000000     0 OBJECT  LOCAL  DEFAULT    1 gcc2_compiled.

14: 00100450     0 NOTYPE  LOCAL  DEFAULT               0x4 __gnu_compiled_c
15: 00100450     0 NOTYPE  LOCAL  DEFAULT               0x4 gcc2_compiled.

[1superchip]

464: 0024b210 0 NOTYPE LOCAL DEFAULT 1 __gnu_compiled_cplusplus