Eolian/Lexer: fix EOF issue.

When a new line was added before the last } in a .eo file, the parsing
was resulting in an error. It was due to the fact that some pointer
indicating the eof was not set when the parsing was done from memory.

src/lib/eolian/eo_lexer.rl

@@ -1075,6 +1075,8 @@ eo_tokenizer_mem_walk(Eo_Tokenizer *toknz, const char *source, char *buffer, uns
 
    toknz->pe = toknz->p + len;
 
+   toknz->eof = toknz->pe;
+
    %% write exec;
 
    if ( toknz->cs == %%{ write error; }%% )