floss: Fix build for arm cross-compiling

ARM builds complain about incorrect size for c_char (u8 vs i8) so use
the actual raw character type instead.

Also add build scripts for all binaries so that pkg-config correctly
adds the correct libdir to the search paths.

Bug: 201687614
Tag: #floss
Test: ./build.py; emerge-zork-floss floss; emerge-trogdor floss;
Change-Id: I32e6975e4def090da4ce2e9661b4d623615615d2