Declare default outputs from nogo_stdlib

nogo_stdlib propogate facts and findings to downstream nogo_aspects via
NogoStdlibInfo. This all works fine except one case: directly building a
nogo_stdlib. e.g., bazel build //tools/nogo:stdlib.

In this case, nothing is requesting the NogoStdlibInfo, and thus the target has
nothing to do. This can be rather confusing when trying to debug failures in
:stdlib, as building :stdlib does nothing.

Fix this by declaring the facts and findings as default outputs from
nogo_stdlib. Now direct bazel build will request these outputs and actually
trigger the analysis. Standard aspect builds are unaffected.

PiperOrigin-RevId: 391580126

tools/nogo/defs.bzl

@@ -160,6 +160,11 @@ def _nogo_stdlib_impl(ctx):
     return [NogoStdlibInfo(
         facts = facts,
         raw_findings = raw_findings,
+    ), DefaultInfo(
+        # Declare the facts and findings as default outputs. This is not
+        # strictly required, but ensures that the target still perform analysis
+        # when built directly rather than just indirectly via a nogo_test.
+        files = depset([facts, raw_findings]),
     )]
 
 nogo_stdlib = go_rule(