HostToolPath should return install path

Bug: 163154468
Test: make; find dependencies of 'Module:  sqlite3_bindgen_x86_64'
Change-Id: Id9fc4f1937983bdf7eb1732ed6a8afd5aa3eb24c
diff --git a/rust/binary_test.go b/rust/binary_test.go
index ab2dae1..b9c8698 100644
--- a/rust/binary_test.go
+++ b/rust/binary_test.go
@@ -36,6 +36,11 @@
 	fizzBuzz := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64").Output("fizz-buzz")
 	fizzBuzzDynamic := ctx.ModuleForTests("fizz-buzz-dynamic", "linux_glibc_x86_64").Output("fizz-buzz-dynamic")
 
+	path := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64").Module().(*Module).HostToolPath()
+	if g, w := path.String(), "/host/linux-x86/bin/fizz-buzz"; !strings.Contains(g, w) {
+		t.Errorf("wrong host tool path, expected %q got %q", w, g)
+	}
+
 	// Do not compile binary modules with the --test flag.
 	flags := fizzBuzzDynamic.Args["rustcFlags"]
 	if strings.Contains(flags, "--test") {
diff --git a/rust/rust.go b/rust/rust.go
index edfa5d8..46159c6 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -1057,8 +1057,8 @@
 	if !mod.Host() {
 		return android.OptionalPath{}
 	}
-	if _, ok := mod.compiler.(*binaryDecorator); ok {
-		return mod.outputFile
+	if binary, ok := mod.compiler.(*binaryDecorator); ok {
+		return android.OptionalPathForPath(binary.baseCompiler.path)
 	}
 	return android.OptionalPath{}
 }