[libFuzzer] [NFC] Generalize fdmask test.

[george.karpenkov]

Summary

The ordering of stderr/stdout writes might not be guaranteed,

and is irrelevant for this test.

[morehouse]

Since the test flushes output after each write to stdout, why is ordering not guaranteed here?

[george.karpenkov]

@morehouse we have issues with stdout/stderr arriving in unexpected order when run on devices and streaming across the network.
In this case adding -DAG seems like an easiest choice, since the test purpose is to check that close_fd_mask would close the corresponding file descriptor.

test/fuzzer/fuzzer-fdmask.test

 RUN: %cpp_compiler %S/SpamyTest.cpp -o %t-SpamyTest
 
 RUN: %run %t-SpamyTest -runs=1                  2>&1 | FileCheck %s --check-prefix=FD_MASK_0
 RUN: %run %t-SpamyTest -runs=1 -close_fd_mask=0 2>&1 | FileCheck %s --check-prefix=FD_MASK_0
 RUN: %run %t-SpamyTest -runs=1 -close_fd_mask=1 2>&1 | FileCheck %s --check-prefix=FD_MASK_1
 RUN: %run %t-SpamyTest -runs=1 -close_fd_mask=2 2>&1 | FileCheck %s --check-prefix=FD_MASK_2
 RUN: %run %t-SpamyTest -runs=1 -close_fd_mask=3 2>&1 | FileCheck %s --check-prefix=FD_MASK_3
 
-FD_MASK_0: PRINTF_STDOUT
-FD_MASK_0: PRINTF_STDERR
-FD_MASK_0: STREAM_COUT
-FD_MASK_0: STREAM_CERR
-FD_MASK_0: INITED
+FD_MASK_0-DAG: PRINTF_STDOUT
+FD_MASK_0-DAG: PRINTF_STDERR
+FD_MASK_0-DAG: STREAM_COUT
+FD_MASK_0-DAG: STREAM_CERR
+FD_MASK_0-DAG: INITED
 
 FD_MASK_1-NOT: PRINTF_STDOUT
-FD_MASK_1: PRINTF_STDERR
+FD_MASK_1-DAG: PRINTF_STDERR
 FD_MASK_1-NOT: STREAM_COUT
-FD_MASK_1: STREAM_CERR
-FD_MASK_1: INITED
+FD_MASK_1-DAG: STREAM_CERR
+FD_MASK_1-DAG: INITED
 
-FD_MASK_2: PRINTF_STDOUT
+FD_MASK_2-DAG: PRINTF_STDOUT
+FD_MASK_2-DAG: STREAM_COUT
+FD_MASK_2-DAG: INITED
 FD_MASK_2-NOT: PRINTF_STDERR
-FD_MASK_2: STREAM_COUT
-FD_MASK_2-NOTE: STREAM_CERR
-FD_MASK_2: INITED
+FD_MASK_2-NOT: STREAM_CERR
 
 FD_MASK_3-NOT: PRINTF_STDOUT
 FD_MASK_3-NOT: PRINTF_STDERR
 FD_MASK_3-NOT: STREAM_COUT
 FD_MASK_3-NOT: STREAM_CERR
 FD_MASK_3: INITED