Do not copy libstd dynamic library to sysroot

src/bootstrap/src/bin/rustc.rs

@@ -95,7 +95,6 @@ fn main() {
     // When statically linking `std` into `rustc_driver`, remove `-C prefer-dynamic`
     if env::var("RUSTC_LINK_STD_INTO_RUSTC_DRIVER").unwrap() == "1"
         && crate_name == Some("rustc_driver")
-        && stage != "0"
     {
         if let Some(pos) = args.iter().enumerate().position(|(i, a)| {
             a == "-C" && args.get(i + 1).map(|a| a == "prefer-dynamic").unwrap_or(false)

src/bootstrap/src/core/build_steps/compile.rs

@@ -1923,8 +1923,24 @@ impl Step for Assemble {
         let src_libdir = builder.sysroot_libdir(build_compiler, host);
         for f in builder.read_dir(&src_libdir) {
             let filename = f.file_name().into_string().unwrap();
-            if (is_dylib(&filename) || is_debug_info(&filename)) && !proc_macros.contains(&filename)
+
+            let is_proc_macro = proc_macros.contains(&filename);
+            let is_dylib_or_debug = is_dylib(&filename) || is_debug_info(&filename);
+
+            // If we link statically to stdlib, do not copy the libstd dynamic library file
+            // Currently, we do not avoid the copy on Windows, as it seems to be causing issues in
+            // post-optimization stage0 tests.
+            let can_be_rustc_dynamic_dep = if builder
+                .link_std_into_rustc_driver(target_compiler.host)
+                && !target_compiler.host.is_windows()
             {
+                let is_std = filename.starts_with("std-") || filename.starts_with("libstd-");
+                !is_std
+            } else {
+                true
+            };
+
+            if is_dylib_or_debug && can_be_rustc_dynamic_dep && !is_proc_macro {
                 builder.copy_link(&f.path(), &rustc_libdir.join(&filename));
             }
         }