Make sure public functions parameters are unaffected by argument prom…

…otion

In order for a prototype declaration and non-prototype function
definition to be compatible, the promoted type of the non-prototype
function parameters must be compatible with the type of the corresponding
prototype parameter.

Since funcs.h is autogenerated by mkfuncs.pl which copies the parameter
types as-is, use the promoted type in the definitions so that the types
are unaffected by default argument promotion.

Fixes gwsw#11

charset.c

@@ -502,7 +502,7 @@ prutfchar(ch)
  */
  public int
 utf_len(ch)
- unsigned char ch;
+ int ch;
 {
  if ((ch & 0x80) == 0)
  return 1;

line.c

@@ -787,7 +787,7 @@ flush_mbc_buf(pos)
  */
  public int
 pappend(c, pos)
- unsigned char c;
+ int c;
  POSITION pos;
 {
  int r;
@@ -1157,7 +1157,7 @@ pdone(endline, chopped, forw)
  */
  public void
 set_status_col(c)
- char c;
+ int c;
 {
  set_linebuf(0, c, AT_NORMAL|AT_HILITE);
 }