Suppress -Wconversion warnings

Change-Id: Ie23e1c2c450e89b1a042cae6ebab36945bea2c94
Reviewed-on: https://fuchsia-review.googlesource.com/c/libc-tests/+/516960
Reviewed-by: Shai Barack <shayba@google.com>
Commit-Queue: Dangyi Liu <dangyi@google.com>
diff --git a/third_party/nacl-ported-tests/threads/BUILD.gn b/third_party/nacl-ported-tests/threads/BUILD.gn
index 48ac5d7..07f2d69 100644
--- a/third_party/nacl-ported-tests/threads/BUILD.gn
+++ b/third_party/nacl-ported-tests/threads/BUILD.gn
@@ -27,6 +27,9 @@
   deps = [
     "//third_party/googletest:gtest",
   ]
+
+  # TODO(fxbug.dev/58162): delete the below and fix compiler warnings
+  configs += [ "//build/config:Wno-conversion" ]
 }
 
 source_set("large_tests_broken") {