[TIR] ConvertSSA process entry func first (apache#16236)

* convert ssa process entry func first

* add doc

src/tir/transforms/ir_utils.cc

@@ -715,8 +715,13 @@ Pass ConvertSSA() {
     tir::IRConvertSSA converter;
     Map<GlobalVar, BaseFunc> functions;
     bool made_change = false;
+    // FIXME: This is just a temporal workaround to ensure free vars
+    // in device function have the same pointer as the host function
     for (auto [gvar, base_func] : mod->functions) {
       if (auto* ptr = base_func.as<tir::PrimFuncNode>()) {
+        if (!ptr->HasNonzeroAttr(tir::attr::kIsEntryFunc)) {
+          continue;
+        }
         auto updated = converter.VisitPrimFunc(GetRef<tir::PrimFunc>(ptr));
         if (!updated.same_as(base_func)) {
           made_change = true;
@@ -725,6 +730,19 @@ Pass ConvertSSA() {
       }
       functions.Set(gvar, base_func);
     }
+    for (auto [gvar, base_func] : mod->functions) {
+      if (auto* ptr = base_func.as<tir::PrimFuncNode>()) {
+        if (ptr->HasNonzeroAttr(tir::attr::kIsEntryFunc)) {
+          continue;
+        }
+        auto updated = converter.VisitPrimFunc(GetRef<tir::PrimFunc>(ptr));
+        if (!updated.same_as(base_func)) {
+          made_change = true;
+          base_func = updated;
+        }
+        functions.Set(gvar, base_func);
+      }
+    }
     if (made_change) {
       mod.CopyOnWrite()->functions = std::move(functions);
     }