goose: allow multiple arguments to use and import

Reviewed-by: Tuo Shan <shantuo@google.com>

internal/goose/testdata/MultiImport/foo/foo.go

@@ -0,0 +1,22 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(injectFooBar())
+}
+
+type Foo int
+type FooBar int
+
+//goose:provide Foo
+func provideFoo() Foo {
+	return 41
+}
+
+//goose:provide FooBar
+func provideFooBar(foo Foo) FooBar {
+	return FooBar(foo) + 1
+}
+
+//goose:import Set Foo FooBar