cmd/cc: change getquoted() to accept whitespaces.

getquoted() currently checks for whitespaces and returns nil
if it finds one. this prevents us from having go in a path
containing whitespaces, as the #pragma dynld directives are
processed through the said function.

this commit makes getquoted() accept whitespaces, and this is
also needed for solving issue #115.

R=rsc
https://golang.org/cl/157066

src/cmd/cc/dpchk.c

@@ -214,7 +214,7 @@ getquoted(void)
 	fmtstrinit(&fmt);
 	for(;;) {
 		r = getr();
-		if(r == ' ' || r == '\n') {
+		if(r == '\n') {
 			free(fmtstrflush(&fmt));
 			return nil;
 		}