use same indent and flush output in genconstants.c

* using tabs as indents, rather than mixture of tabs/spaces
* flush stdout/stderr just to be extra safe (wasn't not needed so far)
* add commented out segfault-causing line when testing build.rs manually
  This segfault needs to be done before initscr/endwin or else the terminal
  seems messed up and you've to run 'reset' to restore it, plus you
  don't see the outputs properly.

src/genconstants.c

@@ -4,11 +4,12 @@
 #define PCONSTU(ty, NAME) printf("pub const " #NAME ": " #ty " = %llu;\n", (unsigned long long) (NAME))
 
 int main() {
- /* some values aren't set until after this is run */
- printf("//");
+ /* some values aren't set until after this is run */
+ printf("//");
+ //fflush(stdout);fflush(stderr);*((int *)0) = 42; //segfault(on purpose for testing purposes) before terminal gets messed up needing a `reset` shell command to restore!
  initscr();
  endwin();
- printf("\n");
+ printf("\n");
 
  /* Success/Failure. */
  PCONST(i32, ERR);
@@ -296,4 +297,7 @@ int main() {
  PCONSTU(crate::ll::chtype, A_ATTRIBUTES);
  PCONSTU(crate::ll::chtype, A_CHARTEXT);
  PCONSTU(crate::ll::chtype, A_COLOR);
+
+ //do last, flush just to be sure!
+ fflush(stdout);fflush(stderr);
 }