Don't run strong mode vm tests on simdbc64 until we figure out why it's acting architecture specific.

Bug:
Change-Id: Iacc78a249662c2b547ea9fe9347c09834e6277ac
Reviewed-on: https://dart-review.googlesource.com/30700
Reviewed-by: Emily Fortuna <[email protected]>
Commit-Queue: Emily Fortuna <[email protected]>

Author: efortuna

tests/standalone_2/standalone_2.status

@@ -58,6 +58,9 @@ io/addlatexhash_test: Skip
 [ !$strong ]
 float_array_static_test: MissingCompileTimeError
 
+[ $arch == simdbc64 && $strong && ($compiler == dartk || $compiler == dartkp) ]
+io/*: Skip # Issue 31695
+
 [ $builder_tag == swarming && $system == macos ]
 io/*: Skip # Issue 30618