ASSERT "NULL:0 NULL" Android linux.signal0111 test

This happened once in a test suite. Xref #2107, #2053.

```
android-debug-internal-32: 71 tests passed, **** 1 tests failed: ****
code_api|linux.signal0111 => Application /data/local/tmp/build_android-debug-internal-32/suite/tests/bin/linux.signal0111 (4314). Internal Error: DynamoRIO debug check failure: NULL:0 NULL
```

```
21/72 Testing: code_api|linux.signal0111
21/72 Test: code_api|linux.signal0111
Command: "/extsw/android/android-sdk-linux/platform-tools/adb" "shell" "/data/local/tmp/build_android-debug-internal-32/bin32/drrun" "-s" "90" "-quiet" "-debug" "-killpg" "-stderr_mask" "0xC" "-dumpcore_mask" "0" "-code_api" "--" "/data/local/tmp/build_android-debug-internal-32/suite/tests/bin/linux.signal0111"
Directory: /work/dr/build_foo/build_android-debug-internal-32/suite/tests
"code_api|linux.signal0111" start time: Dec 12 15:11 EST
Output:
----------------------------------------------------------
:0
(Error occurred @3452 frags)
version 6.2.17147, custom build
-no_dynamic_options -code_api -stderr_mask 12 -stack_size 56K -max_elide_jmp 0 -max_elide_call 0 -early_inject -emulate_brk -no_inline_ignored_syscalls -native_exec_default_list '' -no_native_exec_managed_code -no_indcall2direct
0xb6d0486d 0x78af04b0>

Test time = 13.92 sec
```