Add regression test for #59137.

src/test/run-make-fulldeps/lto-dylib-dep/Makefile

@@ -0,0 +1,10 @@
+-include ../tools.mk
+
+# Test that we don't run into an assertion when using a Rust dylib dependency
+# while compiling with full LTO.
+# See https://github.com/rust-lang/rust/issues/59137
+
+all:
+	$(RUSTC) a_dylib.rs --crate-type=dylib -C prefer-dynamic
+	$(RUSTC) main.rs -C lto
+	$(call RUN,main)

src/test/run-make-fulldeps/lto-dylib-dep/a_dylib.rs

@@ -0,0 +1,4 @@
+
+pub fn foo() {
+    println!("bar");
+}

src/test/run-make-fulldeps/lto-dylib-dep/main.rs

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+
+extern crate a_dylib;
+
+fn main() {
+    a_dylib::foo();
+}