bazel,colexec: generate crossjoiner.eg.go within bazel

We broke the bazel build in 52c5f51 when we introduced a new .eg.go
file, without updating the bazel target. We do that here.

Fixes: cockroachdb#59052.

Release note: None

pkg/sql/colexec/COLEXEC.bzl

@@ -3,6 +3,7 @@ targets = [
     ('and_or_projection.eg.go', 'and_or_projection_tmpl.go'),
     ('cast.eg.go', 'cast_tmpl.go'),
     ('const.eg.go', 'const_tmpl.go'),
+    ('crossjoiner.eg.go', 'crossjoiner_tmpl.go'),
     ('default_cmp_expr.eg.go', 'default_cmp_expr_tmpl.go'),
     ('default_cmp_proj_ops.eg.go', 'default_cmp_proj_ops_tmpl.go'),
     ('default_cmp_sel_ops.eg.go', 'default_cmp_sel_ops_tmpl.go'),

pkg/sql/colexec/crossjoiner_tmpl.go

@@ -23,11 +23,20 @@ import (
 	"context"
 
 	"github.com/cockroachdb/cockroach/pkg/col/coldata"
+	"github.com/cockroachdb/cockroach/pkg/col/typeconv"
 	"github.com/cockroachdb/cockroach/pkg/sql/colexec/execgen"
 	"github.com/cockroachdb/cockroach/pkg/sql/colexecbase/colexecerror"
+	"github.com/cockroachdb/cockroach/pkg/sql/types"
 	"github.com/cockroachdb/errors"
 )
 
+// Workaround for bazel auto-generated code. goimports does not automatically
+// pick up the right packages when run within the bazel sandbox.
+var (
+	_ = typeconv.DatumVecCanonicalTypeFamily
+
+)
+
 // buildFromLeftInput builds part of the output of a cross join that comes from
 // the vectors of the left input. The new output tuples are put starting at
 // index destStartIdx and will not exceed the capacity of the output batch. It