6a, 6c, 6l: fix for Plan 9 build

6a/a.h:
. Dropped <u.h> and <libc.h>.
. Made definition of EOF conditional.

6a/a.y:
. Added <u.h> and <libc.h>.

6a/lex.c:
. Added <u.h> and <libc.h>.
. Dropped <ctype.h> (now in <u.h>).

6c/gc.h:
. Added varargck pragma for "lD".

6c/swt.c:
. Dropped unused "thestring" argument in Bprint() calls.

6l/Makefile:
. Dropped unneeded directory prefix.

6l/l.h:
. Dropped unneeded directory prefix.
. Added varargck pragma for "I" and "i".

6l/obj.c:
. Dropped unneeded assignment.
. Dropped unreachable goto statement.

6l/pass.c:
. Dropped assignments flagged as unused.

6l/prof.c:
. Replaced "#if 0" with "#ifdef NOTDEF".

6l/span.c:
. Dropped unused incrementation.
. Added USED() as required.
. Dropped unreachable "return" statement.

R=golang-dev
CC=golang-dev, rsc
https://golang.org/cl/4747044

src/cmd/6a/a.h

@@ -28,8 +28,6 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-#include <u.h>
-#include <libc.h>
 #include <bio.h>
 #include "../6l/6.out.h"
 
@@ -57,7 +55,9 @@ typedef	struct	Gen2	Gen2;
 #define	NSYMB		500
 #define	BUFSIZ		8192
 #define	HISTSZ		20
+#ifndef	EOF
 #define	EOF		(-1)
+#endif
 #define	IGN		(-2)
 #define	GETC()		((--fi.c < 0)? filbuf(): *fi.p++ & 0xff)
 #define	NHASH		503

src/cmd/6a/a.y

@@ -29,7 +29,9 @@
 // THE SOFTWARE.
 
 %{
+#include <u.h>
 #include <stdio.h>	/* if we don't, bison will, and a.h re-#defines getc */
+#include <libc.h>
 #include "a.h"
 %}
 %union	{

src/cmd/6a/lex.c

@@ -29,9 +29,10 @@
 // THE SOFTWARE.
 
 #define	EXTERN
+#include <u.h>
+#include <libc.h>
 #include "a.h"
 #include "y.tab.h"
-#include <ctype.h>
 
 enum
 {

src/cmd/6c/gc.h

@@ -398,6 +398,7 @@ void	shiftit(Type*, Node*, Node*);
 #pragma	varargck	type	"A"	int
 #pragma	varargck	type	"B"	Bits
 #pragma	varargck	type	"D"	Adr*
+#pragma	varargck	type	"lD"	Adr*
 #pragma	varargck	type	"P"	Prog*
 #pragma	varargck	type	"R"	int
 #pragma	varargck	type	"S"	char*

src/cmd/6c/swt.c

@@ -238,10 +238,10 @@ outcode(void)
 		Bprint(&b, "\n");
 		Bprint(&b, "$$  // exports\n\n");
 		Bprint(&b, "$$  // local types\n\n");
-		Bprint(&b, "$$  // dynimport\n", thestring);
+		Bprint(&b, "$$  // dynimport\n");
 		for(i=0; i<ndynimp; i++)
 			Bprint(&b, "dynimport %s %s %s\n", dynimp[i].local, dynimp[i].remote, dynimp[i].path);
-		Bprint(&b, "\n$$  // dynexport\n", thestring);
+		Bprint(&b, "\n$$  // dynexport\n");
 		for(i=0; i<ndynexp; i++)
 			Bprint(&b, "dynexport %s %s\n", dynexp[i].local, dynexp[i].remote);
 		Bprint(&b, "\n$$\n\n");

src/cmd/6l/Makefile

@@ -30,7 +30,7 @@ OFILES=\
 
 HFILES=\
 	l.h\
-	../6l/6.out.h\
+	6.out.h\
 	../ld/lib.h\
 	../ld/elf.h\
 	../ld/macho.h\

src/cmd/6l/l.h

@@ -31,7 +31,7 @@
 #include	<u.h>
 #include	<libc.h>
 #include	<bio.h>
-#include	"../6l/6.out.h"
+#include	"6.out.h"
 
 #ifndef	EXTERN
 #define	EXTERN	extern
@@ -301,9 +301,11 @@ EXTERN union
 
 #pragma	varargck	type	"A"	uint
 #pragma	varargck	type	"D"	Adr*
+#pragma	varargck	type	"I"	uchar*
 #pragma	varargck	type	"P"	Prog*
 #pragma	varargck	type	"R"	int
 #pragma	varargck	type	"S"	char*
+#pragma	varargck	type	"i"	char*
 
 EXTERN	int32	HEADR;
 EXTERN	int32	HEADTYPE;

src/cmd/6l/obj.c

@@ -455,7 +455,6 @@ loop:
 		s = lookup(x, r);
 		if(x != name)
 			free(x);
-		name = nil;
 
 		if(debug['S'] && r == 0)
 			sig = 1729;
@@ -724,7 +723,6 @@ loop:
 		lastp = p;
 		goto loop;
 	}
-	goto loop;
 
 eof:
 	diag("truncated object file: %s", pn);

src/cmd/6l/pass.c

@@ -402,8 +402,6 @@ dostkoff(void)
 		pmorestack[i] = symmorestack[i]->text;
 	}
 
-	autoffset = 0;
-	deltasp = 0;
 	for(cursym = textp; cursym != nil; cursym = cursym->next) {
 		if(cursym->text == nil || cursym->text->link == nil)
 			continue;
@@ -415,7 +413,6 @@ dostkoff(void)
 			autoffset = 0;
 
 		q = P;
-		q1 = P;
 		if((p->from.scale & NOSPLIT) && autoffset >= StackSmall)
 			diag("nosplit func likely to overflow stack");
 
@@ -471,7 +468,6 @@ dostkoff(void)
 				p = appendp(p);
 				p->as = ANOP;
 				q1->pcond = p;
-				q1 = P;
 			}
 
 			if(autoffset < StackBig) {  // do we need to call morestack?
@@ -611,7 +607,6 @@ dostkoff(void)
 			p = appendp(p);
 			p->as = ANOP;
 			q1->pcond = p;
-			q1 = P;
 		}
 		
 		for(; p != P; p = p->link) {

src/cmd/6l/prof.c

@@ -36,7 +36,7 @@
 void
 doprof1(void)
 {
-#if 0
+#ifdef	NOTDEF
 	Sym *s;
 	int32 n;
 	Prog *p, *q;

src/cmd/6l/span.c

@@ -94,7 +94,7 @@ span1(Sym *s)
 					*bp++ = v;
 					*bp++ = v>>8;
 					*bp++ = v>>16;
-					*bp++ = v>>24;
+					*bp = v>>24;
 				}	
 			}
 			p->comefrom = P;
@@ -706,6 +706,7 @@ asmandsz(Adr *a, int r, int rex, int m64)
 	int t, scale;
 	Reloc rel;
 
+	USED(m64);
 	rex &= (0x40 | Rxr);
 	v = a->offset;
 	t = a->type;
@@ -732,7 +733,6 @@ asmandsz(Adr *a, int r, int rex, int m64)
 			*andptr++ = (0 << 6) | (4 << 0) | (r << 3);
 			asmidx(a->scale, a->index, t);
 			goto putrelv;
-			return;
 		}
 		if(v == 0 && rel.siz == 0 && t != D_BP && t != D_R13) {
 			*andptr++ = (0 << 6) | (4 << 0) | (r << 3);