Add icc in mcxx to enable imc* wrappers

bsc/mcxx/default.nix

@@ -10,6 +10,7 @@
 , flex
 , bison
 , gcc
+, icc
 }:
 
 stdenv.mkDerivation rec {
@@ -37,6 +38,7 @@ stdenv.mkDerivation rec {
     bison
     flex
     gcc
+    icc
   ];
 
   configureFlags = [

default.nix

@@ -36,6 +36,7 @@ let
     };
 
     # Default Intel MPI version is 2019 (the last one)
+    impi = intel-mpi;
     intel-mpi = intel-mpi-2019;
     intel-mpi-2019 = callPackage ./bsc/intel-mpi/default.nix {
       # Intel MPI provides a debug version of the MPI library, but
@@ -70,6 +71,7 @@ let
     };
 
     mcxx = callPackage ./bsc/mcxx/default.nix {
+      icc = icc;
       stdenv = pkgs.gcc9Stdenv;
       nanos6 = nanos6-git;
     };