Merge "Add opt-in option to turn on ThinLTO caching"

		var ltoFlag string

		if Bool(lto.Properties.Lto.Thin) {

			ltoFlag = "-flto=thin"

		} else {

			ltoFlag = "-flto"

		}

		flags.CFlags = append(flags.CFlags, ltoFlag)

		flags.LdFlags = append(flags.LdFlags, ltoFlag)

		if ctx.Config().IsEnvTrue("USE_THINLTO_CACHE") && Bool(lto.Properties.Lto.Thin) {

			// Set appropriate ThinLTO cache policy

			cacheDirFormat := "-Wl,-plugin-opt,cache-dir="

			cacheDir := android.PathForOutput(ctx, "thinlto-cache").String()

			flags.LdFlags = append(flags.LdFlags, cacheDirFormat+cacheDir)

			// Limit the size of the ThinLTO cache to the lesser of 10% of available

			// disk space and 10GB.

			cachePolicyFormat := "-Wl,-plugin-opt,cache-policy="

			policy := "cache_size=10%:cache_size_bytes=10g"

			flags.LdFlags = append(flags.LdFlags, cachePolicyFormat+policy)

		}

		if ctx.Device() {

			// Work around bug in Clang that doesn't pass correct emulated

			// TLS option to target. See b/72706604 or