Random crash during disassembling with `fteqcc`

[alexey-lysiuk]

Attempt to disassemble progs.dat from Something Wicked This Way Comes via fteqcc -d crashes randomly at this location.

QC_snprintfz(fname, sizeof(fname), "%s %s", builtins[bi].text, GetString(functions[i].s_name));

DecompileCalcProfiles at decomp.c:1119:5
DecompileDecompileFunctions() at decomp.c:3291:2
DecompileProgsDat() at decomp.c:3431:2
DoDecompileProgsDat() at qcctui.c:208:2
main() at qcctui.c:409:6

Value of functions[1].s_name seems to be random, in addition to signed/unsigned mismatch of string_t and dstring_t definitions when calling GetString() function.

Reproduced with the current HEAD, 0976808.