lib9: fix needsrcquote

As written, it is passing a rune to strchr, which likely ignores
all but the bottom 8 bits of the rune. Long-standing Plan 9 bug too.

Fixes #87.

Change-Id: I6a833373b308bed8760d6989972c7f77b4ef3838
Reviewed-on: https://plan9port-review.googlesource.com/2921
Reviewed-by: Russ Cox <rsc@swtch.com>

src/lib9/needsrcquote.c

diff --git a/src/lib9/needsrcquote.c b/src/lib9/needsrcquote.c
index f4cf460..a9e62bc 100644
--- a/src/lib9/needsrcquote.c
+++ b/src/lib9/needsrcquote.c
@@ -4,7 +4,7 @@
 int
 needsrcquote(int c)
 {
-	if(c <= ' ')
+	if(c <= ' ' || c >= 0x80)
 		return 1;
 	if(strchr("`^#*[]=|\\?${}()'<>&;", c))
 		return 1;