fix possible infinite recursion in eqtype.

don't use intermediate register to move
32-or-fewer-bit immediate constants
into memory.

R=ken
OCL=23726
CL=23726

src/cmd/6g/gsubr.c

@@ -554,7 +554,9 @@ gmove(Node *f, Node *t)
 		goto st;
 
 	st:
-		if(f->op == OCONST) {
+		// 64-bit immediates only allowed for move into registers.
+		// this is not a move into a register.
+		if(f->op == OCONST || (f->op == OLITERAL && !t64)) {
 			gins(a, f, t);
 			return;
 		}

src/cmd/gc/subr.c

@@ -1620,7 +1620,7 @@ signame(Type *t)
 	// so that it can be referred to by the runtime.
 	if(strcmp(buf, "interface { }") == 0)
 		strcpy(buf, "empty");
-	
+
 	// special case: sigi.... is just too hard to read in assembly.
 	if(strcmp(buf, "...") == 0)
 		strcpy(buf, "dotdotdot");
@@ -1707,7 +1707,7 @@ eqtype(Type *t1, Type *t2, int d)
 					return 0;
 				if(ta->etype != TFIELD || tb->etype != TFIELD)
 					return 0;
-				if(!eqtype(ta->type, tb->type, 0))
+				if(!eqtype(ta->type, tb->type, d+1))
 					return 0;
 				ta = ta->down;
 				tb = tb->down;