feat(nix): add wasi32 cross target

Signed-off-by: Drew Hess <src@drewhess.com>

Author: dhess

flake.nix

@@ -85,7 +85,9 @@
           # haskell.nix does a lot of heavy lifiting for us and gives us a
           # flake for our Cabal project with the following attributes:
           # `checks`, `apps`, and `packages`.
-          primerFlake = pkgs.primer.flake { };
+          primerFlake = pkgs.primer.flake {
+	    crossPlatforms = p: [ p.wasi32 ];
+	  };
 
           weeder =
             let
@@ -424,6 +426,8 @@
                 ];
 
                 shell = {
+		  crossPlatforms = p: [ p.wasi32 ];
+
                   # We're using a `source-repository-package`, so we must disable this.
                   # See:
                   # https://github.com/hackworthltd/primer/issues/876
@@ -468,7 +472,9 @@
                 };
               };
 
-              primerFlake = primer.flake { };
+              primerFlake = primer.flake {
+		crossPlatforms = p: [p.wasi32 ];
+	      };
 
               # Note: these benchmarks should only be run (in CI) on a
               # "benchmark" machine. This is enforced for our CI system