rustc: Fix some ThinLTO internalization

First the `addPreservedGUID` function forgot to take care of "alias" summaries.
I'm not 100% sure what this is but the current code now matches upstream. Next
the `computeDeadSymbols` return value wasn't actually being used, but it needed
to be used! Together these should...

Closes #45195

2 files changed, 33 insertions, 0 deletions

diff --git a/src/test/run-pass/thinlto/auxiliary/dylib.rs b/src/test/run-pass/thinlto/auxiliary/dylib.rs
new file mode 100644
index 00000000000..cdb3f49cae8
--- /dev/null
+++ b/src/test/run-pass/thinlto/auxiliary/dylib.rs
@@ -0,0 +1,16 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags: -Z thinlto -C codegen-units=8
+
+#[inline]
+pub fn foo(b: u8) {
+    b.to_string();
+}
diff --git a/src/test/run-pass/thinlto/auxiliary/thin-lto-inlines-aux.rs b/src/test/run-pass/thinlto/auxiliary/thin-lto-inlines-aux.rs
new file mode 100644
index 00000000000..ccbb0e7a718
--- /dev/null
+++ b/src/test/run-pass/thinlto/auxiliary/thin-lto-inlines-aux.rs
@@ -0,0 +1,17 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// no-prefer-dynamic
+
+#![crate_type = "rlib"]
+
+pub fn bar() -> u32 {
+    3
+}