testdata: fix flakiness of tiny.txt on Windows (#252)

Sometimes it prints relatively low addresses, like:

	(0xbc200,0xdd658)

We required 6 to 8 hex digits, and sometimes it printed 5. Make the
regular expression more conservative.

Fixes #184.

testdata/scripts/tiny.txt

@@ -5,7 +5,7 @@ garble -tiny build
 ! binsubstr main$exe 'main.go' 'fmt/print.go'
 env GODEBUG='allocfreetrace=1,gcpacertrace=1,gctrace=1,inittrace=1,scavenge=1,scavtrace=1,scheddetail=1,schedtrace=10'
 ! exec ./main$exe
-stderr '^\(0x[\d\w]{6,8},0x[\d\w]{6,8}\)' # interfaces/pointers print correctly
+stderr '^\(0x[\d\w]{4,8},0x[\d\w]{4,8}\)' # interfaces/pointers print correctly
 # TODO: Make -tiny remove all line information again.
 # Right now, we reset each declaration's start line to 1.
 # Better than nothing, but we could still make *all* line numbers 1.