build: Make sure to test packages with external tests (backport #7608) (#7635)

* build: Make sure to test packages with external tests (#7608)

The test filter was looking for "TestGoFiles", which does not include tests in
a separate package (e.g., "package foo_test" for "package foo").
This caused several packages not to be tested in CI, including:

  github.com/tendermint/tendermint/abci/client
  github.com/tendermint/tendermint/crypto
  github.com/tendermint/tendermint/crypto/tmhash
  github.com/tendermint/tendermint/internal/eventbus
  github.com/tendermint/tendermint/internal/evidence
  github.com/tendermint/tendermint/internal/inspect
  github.com/tendermint/tendermint/internal/jsontypes
  github.com/tendermint/tendermint/internal/libs/protoio
  github.com/tendermint/tendermint/internal/libs/sync
  github.com/tendermint/tendermint/internal/p2p/pex
  github.com/tendermint/tendermint/internal/pubsub
  github.com/tendermint/tendermint/internal/pubsub/query
  github.com/tendermint/tendermint/internal/pubsub/query/syntax
  github.com/tendermint/tendermint/internal/state/indexer
  github.com/tendermint/tendermint/internal/state/indexer/block/kv
  github.com/tendermint/tendermint/libs/json
  github.com/tendermint/tendermint/libs/log
  github.com/tendermint/tendermint/libs/os
  github.com/tendermint/tendermint/light
  github.com/tendermint/tendermint/light/provider/http
  github.com/tendermint/tendermint/privval/grpc
  github.com/tendermint/tendermint/proto/tendermint/blocksync
  github.com/tendermint/tendermint/proto/tendermint/consensus
  github.com/tendermint/tendermint/proto/tendermint/statesync
  github.com/tendermint/tendermint/rpc/client
  github.com/tendermint/tendermint/rpc/client/mock
  github.com/tendermint/tendermint/test/e2e/tests
  github.com/tendermint/tendermint/test/fuzz/mempool
  github.com/tendermint/tendermint/test/fuzz/p2p/secretconnection
  github.com/tendermint/tendermint/test/fuzz/rpc/jsonrpc/server

Updates #7626 and #7634.

(cherry picked from commit aea428d322)

* Fix build tags to satisfy Go 1.16.

Co-authored-by: M. J. Fromberger <fromberger@interchain.io>

Makefile

@@ -318,9 +318,11 @@ NUM_SPLIT ?= 4
 $(BUILDDIR):
 	mkdir -p $@
 
-# the format statement filters out all packages that don't have tests.
+# The format statement filters out all packages that don't have tests.
+# Note we need to check for both in-package tests (.TestGoFiles) and
+# out-of-package tests (.XTestGoFiles).
 $(BUILDDIR)/packages.txt:$(GO_TEST_FILES) $(BUILDDIR)
-	go list -f "{{ if .TestGoFiles }}{{ .ImportPath }}{{ end }}" ./... | sort > $@
+	go list -f "{{ if (or .TestGoFiles .XTestGoFiles) }}{{ .ImportPath }}{{ end }}" ./... | sort > $@
 
 split-test-packages:$(BUILDDIR)/packages.txt
 	split -d -n l/$(NUM_SPLIT) $< $<.

internal/p2p/pex/reactor_test.go

@@ -1,3 +1,7 @@
+// Temporarily disabled pending ttps://github.com/tendermint/tendermint/issues/7626.
+//go:build issue7626
+//+build issue7626
+
 package pex_test
 
 import (