haskell-modules/generic-builder.nix: work around libc++abi issue

Work around clang’s not linking libc++abi when invoked as `clang` or
`cc` even when it’s needed to link a C++ library or C++ code.

See https://github.com/NixOS/nixpkgs/issues/166205.

pkgs/development/haskell-modules/generic-builder.nix

@@ -811,5 +811,12 @@ stdenv.mkDerivation ({
 // optionalAttrs (args ? dontStrip)              { inherit dontStrip; }
 // optionalAttrs (postPhases != [])              { inherit postPhases; }
 // optionalAttrs (stdenv.buildPlatform.libc == "glibc"){ LOCALE_ARCHIVE = "${glibcLocales}/lib/locale/locale-archive"; }
+
+# Ensure libc++abi is linked even when clang is invoked as just `clang` or `cc`.
+# Works around https://github.com/NixOS/nixpkgs/issues/166205.
+# This can be dropped once a fix has been committed to cc-wrapper.
+// lib.optionalAttrs (stdenv.cc.isClang && stdenv.cc.libcxx != null) {
+  env.NIX_LDFLAGS = "-l${stdenv.cc.libcxx.cxxabi.libName}";
+}
 )
 )