[infra] Fix java coverage (#5747)

* Filter non-fuzz target binaries in coverage script

* Filter non-fuzz target binaries in helper.py

* Fix fuzz target executable bit check in helper.py

Python and JVM fuzz target executables created via the docs template
set the exectuable via `chmod u+x` as the root user, which means that
os.access checks in infra/helper.py don't see the exectuable bit if
not run as root locally.

With this commit, the check now looks for any of the three exectuable
bits.

infra/base-images/base-runner/coverage

@@ -19,7 +19,12 @@ cd $OUT
 if (( $# > 0 )); then
   FUZZ_TARGETS="$@"
 else
-  FUZZ_TARGETS="$(find . -maxdepth 1 -type f -executable -printf '%P\n')"
+  FUZZ_TARGETS="$(find . -maxdepth 1 -type f -executable -printf '%P\n' | \
+      grep -v -x -F \
+      -e 'llvm-symbolizer' \
+      -e 'jazzer_agent_deploy.jar' \
+      -e 'jazzer_driver' \
+      -e 'jazzer_driver_asan')"
 fi
 
 DUMPS_DIR="$OUT/dumps"

infra/helper.py

@@ -680,9 +680,15 @@ def _get_fuzz_targets(project_name):
   for name in os.listdir(_get_out_dir(project_name)):
     if name.startswith('afl-'):
       continue
+    if name.startswith('jazzer_'):
+      continue
+    if name == 'llvm-symbolizer':
+      continue
 
     path = os.path.join(_get_out_dir(project_name), name)
-    if os.path.isfile(path) and os.access(path, os.X_OK):
+    # Python and JVM fuzz targets are only executable for the root user, so
+    # we can't use os.access.
+    if os.path.isfile(path) and (os.stat(path).st_mode & 0o111):
       fuzz_targets.append(name)
 
   return fuzz_targets