emscripten: use matching binaryen version (#37427)

This changes the emscripten package so that it specifies the rev from
the binaryen repo to use, and sets it to always use the version that has
been tagged for use with that version of emscripten.  This should force
future updates of emscripten to also update binaryen.

Binaryen can also be installed as a stand-alone package, so there's some
logic added to the binaryen package to allow building in both ways, and
distinguishing between them.

pkgs/development/compilers/binaryen/default.nix

@@ -1,14 +1,31 @@
-{ stdenv, cmake, fetchFromGitHub }:
+{ stdenv, cmake, fetchFromGitHub, emscriptenRev ? null }:
+
+let
+  defaultVersion = "44";
+
+  # Map from git revs to SHA256 hashes
+  sha256s = {
+    "version_44" = "0zsqppc05fm62807w6vyccxkk2y2gar7kxbxxixq8zz3xsp6w84p";
+    "1.37.36" = "1wgzfzjjzkiaz0rf2lnwrcvlcsjvjhyvbyh58jxhqq43vi34zyjc";
+  };
+in
 
 stdenv.mkDerivation rec {
-  version = "44";
-  rev = "version_${version}";
+  version = if emscriptenRev == null
+            then defaultVersion
+            else "emscripten-${emscriptenRev}";
+  rev = if emscriptenRev == null
+        then "version_${version}"
+        else emscriptenRev;
   name = "binaryen-${version}";
 
   src = fetchFromGitHub {
     owner = "WebAssembly";
     repo = "binaryen";
-    sha256 = "0zsqppc05fm62807w6vyccxkk2y2gar7kxbxxixq8zz3xsp6w84p";
+    sha256 =
+      if builtins.hasAttr rev sha256s
+      then builtins.getAttr rev sha256s
+      else null;
     inherit rev;
   };
 

pkgs/development/compilers/emscripten/default.nix

@@ -5,6 +5,7 @@
 let
   rev = emscriptenVersion;
   appdir = "share/emscripten";
+  binaryenVersioned = binaryen.override { emscriptenRev = rev; };
 in
 
 stdenv.mkDerivation {
@@ -44,7 +45,7 @@ stdenv.mkDerivation {
     echo "SPIDERMONKEY_ENGINE = []" >> $out/${appdir}/config
   ''
   + stdenv.lib.optionalString enableWasm ''
-    echo "BINARYEN_ROOT = '${binaryen}'" >> $out/share/emscripten/config
+    echo "BINARYEN_ROOT = '${binaryenVersioned}'" >> $out/share/emscripten/config
   ''
   +
   ''