Improve pass pipeline (#2328)

Author: MaxGraey

Diff for: src/module.ts

@@ -2464,13 +2464,15 @@ export class Module {
           passes.push("simplify-locals");
           passes.push("coalesce-locals");
         }
+        passes.push("optimize-instructions");
         passes.push("remove-unused-brs");
         passes.push("remove-unused-names");
         passes.push("merge-blocks");
         passes.push("vacuum");
 
-        passes.push("optimize-instructions");
         passes.push("simplify-globals-optimizing");
+        passes.push("remove-unused-brs");
+        passes.push("optimize-instructions");
       }
       // clean up
       passes.push("duplicate-function-elimination");