Fix go.mod, add go.work to use local versions of the dependent modules.

Test: treehugger, (cd build/soong && go build ./...)
Change-Id: I22fd664b5dcc9f4691c5182fdf0dfe53abc0c584
diff --git a/go.work b/go.work
new file mode 100644
index 0000000..737a9df
--- /dev/null
+++ b/go.work
@@ -0,0 +1,19 @@
+go 1.19
+
+use (
+	.
+	../../external/go-cmp
+	../../external/golang-protobuf
+	../../prebuilts/bazel/common/proto/analysis_v2
+	../../prebuilts/bazel/common/proto/build
+	../blueprint
+)
+
+replace (
+	github.com/golang/protobuf v0.0.0 => ../../external/golang-protobuf
+	github.com/google/blueprint v0.0.0 => ../blueprint
+	github.com/google/go-cmp v0.0.0 => ../../external/go-cmp
+	google.golang.org/protobuf v0.0.0 => ../../external/golang-protobuf
+	prebuilts/bazel/common/proto/analysis_v2 v0.0.0 => ../../prebuilts/bazel/common/proto/analysis_v2
+	prebuilts/bazel/common/proto/build v0.0.0 => ../../prebuilts/bazel/common/proto/build
+)