A collection of test cases showing how the new -C prefer-dynamic=crate,... flag can be used to resolve issue 82151.

These differ from the diamonds-*.rs in a couple of ways:
 * The most foundational library is being compiled to multiple crate output types, and
 * The most foundational library is being compiled to a `cdylib`, not a `dylib`.

These two details seemed to be critical for reproducing the exact set of
unfortunate link-time behaviors that we observed on issue 82151, as illustrated
by the family of tests named `issue-82151-serverctl-*.rs`.

----

issue-82151-serverctl-prefdyn.rs works around ld-binary specific details by
adding extra normalization to test, including normalizing stage number in output.

Author: pnkfelix

src/test/ui/dylibs/auxiliary/aaa_issue_82151_bar.rs

@@ -0,0 +1,9 @@
+#![crate_name="bar"]
+#![crate_type="rlib"]
+#![crate_type="cdylib"]
+
+pub struct Bar;
+
+pub fn bar() -> Bar {
+    Bar
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_bar_noprefdyn.rs

@@ -0,0 +1,11 @@
+#![crate_name="bar"]
+#![crate_type="rlib"]
+#![crate_type="cdylib"]
+
+// no-prefer-dynamic
+
+pub struct Bar;
+
+pub fn bar() -> Bar {
+    Bar
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_bar_prefdyn.rs

@@ -0,0 +1,12 @@
+#![crate_name="bar"]
+#![crate_type="rlib"]
+#![crate_type="cdylib"]
+
+// no-prefer-dynamic
+// compile-flags: -C prefer-dynamic
+
+pub struct Bar;
+
+pub fn bar() -> Bar {
+    Bar
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_bar_prefdynstd.rs

@@ -0,0 +1,12 @@
+#![crate_name="bar"]
+#![crate_type="rlib"]
+#![crate_type="cdylib"]
+
+// no-prefer-dynamic
+// compile-flags: -C prefer-dynamic=std -Z prefer-dynamic-std
+
+pub struct Bar;
+
+pub fn bar() -> Bar {
+    Bar
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_bar_prefdynsubset.rs

@@ -0,0 +1,12 @@
+#![crate_name="bar"]
+#![crate_type="rlib"]
+#![crate_type="cdylib"]
+
+// no-prefer-dynamic
+// compile-flags: -C prefer-dynamic=shared,std -Z prefer-dynamic-subset
+
+pub struct Bar;
+
+pub fn bar() -> Bar {
+    Bar
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_foo_noprefdyn.rs

@@ -0,0 +1,13 @@
+#![crate_name="foo"]
+#![crate_type="rlib"]
+
+// no-prefer-dynamic
+
+extern crate bar;
+
+pub struct Foo;
+pub use bar::bar;
+
+pub fn foo() -> Foo {
+    Foo
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_foo_prefdyn.rs

@@ -0,0 +1,14 @@
+#![crate_name="foo"]
+#![crate_type="rlib"]
+
+// no-prefer-dynamic
+// compile-flags: -C prefer-dynamic
+
+extern crate bar;
+
+pub struct Foo;
+pub use bar::bar;
+
+pub fn foo() -> Foo {
+    Foo
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_foo_prefdynstd.rs

@@ -0,0 +1,14 @@
+#![crate_name="foo"]
+#![crate_type="rlib"]
+
+// no-prefer-dynamic
+// compile-flags: -C prefer-dynamic=std -Z prefer-dynamic-std
+
+extern crate bar;
+
+pub struct Foo;
+pub use bar::bar;
+
+pub fn foo() -> Foo {
+    Foo
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_foo_prefdynsubset.rs

@@ -0,0 +1,14 @@
+#![crate_name="foo"]
+#![crate_type="rlib"]
+
+// no-prefer-dynamic
+// compile-flags: -C prefer-dynamic=shared,std -Z prefer-dynamic-subset
+
+extern crate bar;
+
+pub struct Foo;
+pub use bar::bar;
+
+pub fn foo() -> Foo {
+    Foo
+}

src/test/ui/dylibs/auxiliary/aaa_issue_82151_shared_noprefdyn.rs

@@ -0,0 +1,17 @@
+#![crate_name="shared"]
+#![crate_type="dylib"]
+
+// no-prefer-dynamic
+
+extern crate foo;
+
+pub struct Test;
+
+impl Test {
+    pub fn new() -> Self {
+        let _ = foo::foo();
+        let _ = foo::bar();
+        // let _ = bar::bar();
+        Self
+    }
+}