5c, 6c, 8c, 6g, 8g: correct boundary checking

    CL 5666043 fixed the same checking for 5g.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5666045

src/cmd/5c/txt.c

@@ -357,7 +357,7 @@ regfree(Node *n)
 	if(n->op != OREGISTER && n->op != OINDREG)
 		goto err;
 	i = n->reg;
-	if(i < 0 || i >= sizeof(reg))
+	if(i < 0 || i >= nelem(reg))
 		goto err;
 	if(reg[i] <= 0)
 		goto err;

src/cmd/6c/txt.c

@@ -411,7 +411,7 @@ regfree(Node *n)
 	if(n->op != OREGISTER && n->op != OINDREG)
 		goto err;
 	i = n->reg;
-	if(i < 0 || i >= sizeof(reg))
+	if(i < 0 || i >= nelem(reg))
 		goto err;
 	if(reg[i] <= 0)
 		goto err;

src/cmd/6g/gsubr.c

@@ -419,7 +419,7 @@ regfree(Node *n)
 	i = n->val.u.reg;
 	if(i == D_SP)
 		return;
-	if(i < 0 || i >= sizeof(reg))
+	if(i < 0 || i >= nelem(reg))
 		fatal("regfree: reg out of range");
 	if(reg[i] <= 0)
 		fatal("regfree: reg not allocated");

src/cmd/8c/txt.c

@@ -372,7 +372,7 @@ regfree(Node *n)
 	if(n->op != OREGISTER && n->op != OINDREG)
 		goto err;
 	i = n->reg;
-	if(i < 0 || i >= sizeof(reg))
+	if(i < 0 || i >= nelem(reg))
 		goto err;
 	if(reg[i] <= 0)
 		goto err;

src/cmd/8g/gsubr.c

@@ -893,7 +893,7 @@ regfree(Node *n)
 	i = n->val.u.reg;
 	if(i == D_SP)
 		return;
-	if(i < 0 || i >= sizeof(reg))
+	if(i < 0 || i >= nelem(reg))
 		fatal("regfree: reg out of range");
 	if(reg[i] <= 0)
 		fatal("regfree: reg not allocated");