x/perf: build fails on tip

[dmitshur]

From https://build.golang.org/log/245d56a18159497a1da90c35d2bda88f596eb123:

# golang.org/x/perf/vendor/github.com/mattn/go-sqlite3
../../gopath/src/golang.org/x/perf/vendor/github.com/mattn/go-sqlite3/callback.go:331:105: cannot use _cgo2 (type int) as type _Ctype_int in argument to _Cfunc_sqlite3_result_error
../../gopath/src/golang.org/x/perf/vendor/github.com/mattn/go-sqlite3/sqlite3.go:592: cannot use _cgo2 (type int) as type _Ctype_int in argument to _Cfunc__sqlite3_open_v2
../../gopath/src/golang.org/x/perf/vendor/github.com/mattn/go-sqlite3/sqlite3.go:644: cannot use _cgo2 (type int) as type _Ctype_int in argument to _Cfunc_sqlite3_prepare_v2
FAIL	golang.org/x/perf/storage/app [build failed]

The dashboard for x/perf shows the failures have started with Go commit 90df377, and continue with latest Go commit a70a2a8.

It seems related to the recent cmd/cgo changes. Perhaps it's correct behavior and the go-sqlite3 needs to be updated now that #14210 and #25941 are fixed, or perhaps it's a regression in cmd/cgo. /cc @ianlancetaylor @bradfitz

Putting the milestone as Go 1.12 in case it's a problem with cgo; otherwise this should be moved to Unreleased milestone.

[gopherbot]

Change https://golang.org/cl/146900 mentions this issue: cmd/cgo: accept expressions as untyped constants