Fix missing __wasm_apply_data_relocs issue

Author: hamishmack

builder/ghc-for-component-wrapper.nix

@@ -133,9 +133,13 @@ let
      ln -s $wrappedGhc/bin/${ghcCommand}-iserv-prof $wrappedGhc/bin/ghc-iserv-prof
   ''
   # These scripts break if symlinked (they check import.meta.filename against args)
+  # Also for some reason `libdl.so` is missing `__wasm_apply_data_relocs`
   + lib.optionalString (stdenv.hostPlatform.isWasm) ''
      rm $wrappedGhc/lib/*.mjs
      cp $unwrappedGhc/lib/*.mjs $wrappedGhc/lib/
+     substituteInPlace $wrappedGhc/lib/dyld.mjs \
+       --replace-fail "instance.exports.__wasm_apply_data_relocs();" \
+          "if(instance.exports.__wasm_apply_data_relocs) instance.exports.__wasm_apply_data_relocs(); else {}"
   ''
   # Wrap haddock, if the base GHC provides it.
   + ''