8c/gc.h:
. Added <u.h> header.
. Added "lD" pragma for "*Adr" to supplement "D".

8c/swt.c:
. Removed unreferenced "thestring" arguments in Bprint() calls.

cc/acid.c:
cc/com.c:
cc/com64.c:
cc/dcl.c:
cc/scon.c:
. Added <u.h>, required by "cc.h".

cc/bits.c:
. Added <u.h>, required by "cc.h".

cc/cc.h:
. Removed <u.h> and <ctype.h>.
. Added "O" pragma to accept "uint" as well as "int".
. Added new "U" pragma (char *).

cc/cc.y:
. Added <u.h> before <stdio.h> (and "cc.h").

cc/dpchk.c:
cc/mac.c:
. Added <u.h> and <ctype.h>.

cc/funct.c:
. Added <u.h>, required by "cc.h".

cc/godefs.c
. Added <u.h>, required by "cc.h".
. Dropped unused "t" argument in Bprint().

cc/lex.c:
. Added <u.h> and <ctype.h>.
. Removed unnecessary incrementation.
. Changed exit() invocations with exits().

cc/omachcap.c:
. Added <u.h>, required by "cc.h".
. USED(n) for unused argument to machcap().

cc/sub.c:
. Added <u.h> and <ctype.h>.

R=rsc
CC=golang-dev
https://golang.org/cl/4629070