Merge "Enable LTO for Rust dylibs" am: b547b65ed3

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2468260

Change-Id: I212741e0630001b02de9283f413d220508efd89d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

rust/builder.go

@@ -134,6 +134,8 @@ func TransformSrctoRlib(ctx ModuleContext, mainSrc android.Path, deps PathDeps,
 
 func TransformSrctoDylib(ctx ModuleContext, mainSrc android.Path, deps PathDeps, flags Flags,
 	outputFile android.WritablePath) buildOutput {
+	flags.GlobalRustFlags = append(flags.GlobalRustFlags, "-C lto=thin")
+
 	return transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "dylib")
 }
 

rust/config/global.go

@@ -54,6 +54,7 @@ var (
 		// TODO (b/267698452): Temporary workaround until the "no unstable
 		// features" policy is enforced.
 		"-A stable-features",
+		"-Zdylib-lto",
 	}
 
 	deviceGlobalRustFlags = []string{