mold: add tests for `mold-wrapped` and `useMoldLinker` adapter

Make both ready for cross with prefixes

Currently
`pkgsCross.aarch64-multiplatform.mold.passthru.tests.{wrapped,adapter}`
fail with

```
Testing running the 'hello' binary which should be linked with 'mold'
Hello, world!
Checking for mold in the '.comment' section
No mention of 'mold' detected in the '.comment' section
The command was:
aarch64-unknown-linux-gnu-readelf -p .comment ...bin/hello
The output was:
String dump of section '.comment':
  [     0]  GCC: (GNU) 12.3.0
```

1 files changed, 46 insertions, 1 deletions

diff --git a/pkgs/development/tools/mold/default.nix b/pkgs/development/tools/mold/default.nix
index 52844300f0875..84a7509c528c3 100644
--- a/pkgs/development/tools/mold/default.nix
+++ b/pkgs/development/tools/mold/default.nix
@@ -9,6 +9,11 @@
 , testers
 , mold
 , nix-update-script
+, runCommandCC
+, mold-wrapped
+, hello
+, buildPackages
+, useMoldLinker
 }:
 
 stdenv.mkDerivation rec {
@@ -44,7 +49,47 @@ stdenv.mkDerivation rec {
 
   passthru = {
     updateScript = nix-update-script { };
-    tests.version = testers.testVersion { package = mold; };
+    tests =
+      let
+        helloTest = name: helloMold:
+          let
+            command = "$READELF -p .comment ${lib.getExe helloMold}";
+            emulator = stdenv.hostPlatform.emulator buildPackages;
+          in
+          runCommandCC "mold-${name}-test" { passthru = { inherit helloMold; }; }
+            ''
+              echo "Testing running the 'hello' binary which should be linked with 'mold'" >&2
+              ${emulator} ${lib.getExe helloMold}
+
+              echo "Checking for mold in the '.comment' section" >&2
+              if output=$(${command} 2>&1); then
+                if grep -Fw -- "mold" - <<< "$output"; then
+                  touch $out
+                else
+                  echo "No mention of 'mold' detected in the '.comment' section" >&2
+                  echo "The command was:" >&2
+                  echo "${command}" >&2
+                  echo "The output was:" >&2
+                  echo "$output" >&2
+                  exit 1
+                fi
+              else
+                echo -n "${command}" >&2
+                echo " returned a non-zero exit code." >&2
+                echo "$output" >&2
+                exit 1
+              fi
+            ''
+        ;
+      in
+      {
+        version = testers.testVersion { package = mold; };
+        wrapped = helloTest "wrapped" (hello.overrideAttrs (previousAttrs: {
+          nativeBuildInputs = (previousAttrs.nativeBuildInputs or [ ]) ++ [ mold-wrapped ];
+          NIX_CFLAGS_LINK = toString (previousAttrs.NIX_CFLAGS_LINK or "") + " -fuse-ld=mold";
+        }));
+        adapter = helloTest "adapter" (hello.override (old: { stdenv = useMoldLinker old.stdenv; }));
+      };
   };
 
   meta = with lib; {