gazelle generates different load() order when generating a new BUILD file vs. regenerating an existing file.

[treaster]

Running gazelle to generate a new BUILD file results in a different load() vs regenerating an existing file.
When generating a new file, the load() order is determined by the order defined here:
https://github.com/bazelbuild/rules_go/blob/master/go/tools/gazelle/generator/generator.go#L165

When regenerating an existing file, the merge process sorts the entries before producing the output.
https://github.com/bazelbuild/rules_go/blob/master/go/tools/gazelle/merger/merger.go#L142

I would expect gazelle to produce consistent output given consistent input of the go source files.

One possible fix would be to sort the rules list in generator.go.

To reproduce:

mkdir -p gazelle_test/code
cd gazelle_test/
echo "package main\nfunc main() {}" > code/main.go
gazelle --repo_root=. --go_prefix=code
cp code/BUILD  code/BUILD.1
gazelle --repo_root=. --go_prefix=code
diff code/BUILD.1 code/BUILD

Produces

$ diff code/BUILD.1 code/BUILD
1c1
< load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_binary")
---
> load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")

[treaster]

Thanks for the quick fix!!