configure: cleanup

- add quotes: eval opt=\"$opt\"
- use $source_path/conftest.c for OOT build
- add fn_makelink() for OOT build
- do not check lddir etc. on Windows/MSYS
- formatting

config-print.c
- rename to conftest.c (for consistency)
- change option e to b
- change output from that from "yes" to "no"
- remove inttypes.h dependency
- simpify version output

Makefile:
- improve GCC warning flag checks

tcc.h:
- add back default CONFIG_LDDIR
- add default CONFIG_TCCDIR also (just for fun)

tccpp.c:
- fix Christian's last warning
  tccpp.c: In function ‘macro_subst’:
  tccpp.c:2803:12: warning: ‘*((void *)&cval+4)’ is used uninitialized
     in this function [-Wuninitialized]
  That the change fixes the warning doesn't make sense but anyway.

libtcc.c:
- tcc_error/warning: print correct source filename/line for
  token :paste: (also inline :asm:)

lddir and multiarch logic still needs fixing.

tccasm.c

@@ -837,8 +837,7 @@ static void tcc_assemble_inline(TCCState *s1, char *str, int len)
     saved_parse_flags = parse_flags;
     saved_macro_ptr = macro_ptr;
 
-    tcc_open_bf(s1, file->filename, len);
-    file->line_num = file->prev->line_num;
+    tcc_open_bf(s1, ":asm:", len);
     memcpy(file->buffer, str, len);
 
     macro_ptr = NULL;