arm: disable some problematic tests

test/64bit.go:  segfaults on sheevaplug(armv5)

The following have long runtimes when GC is on.
Sample run time in seconds for android emulator
and sheevaplug
test/stack.go:          4934s   1780s
test/ken/chan.go:        860s    296s
test/gc1.go:             218s     69s

R=rsc, kaib
CC=golang-dev
https://golang.org/cl/749041

test/arm-pass.txt

 235.go
-64bit.go
 assign.go
 blank1.go
 chan/fifo.go
@@ -220,7 +219,6 @@ func3.go
 func4.go
 func5.go
 gc.go
-gc1.go
 hashmap.go
 helloworld.go
 if.go
@@ -251,7 +249,6 @@ interface/returntype.go
 interface/struct.go
 iota.go
 ken/array.go
-ken/chan.go
 ken/chan1.go
 ken/complit.go
 ken/divmod.go
@@ -292,7 +289,6 @@ runtime.go
 sieve.go
 sigchld.go
 simassign.go
-stack.go
 string_lit.go
 switch.go
 switch1.go

test/golden-arm.out

 
-=========== 64bit.go
-BUG: 64bit
-
 =========== chan/nonblock.go
 PASS