[turbofan] Fix CodeStubAssembler::ChangeFloat64ToTagged for 32-bit.

Remove the duplicate if_join label (thanks C++ for not even emitting a
warning about this).

R=mtrofin@chromium.org

Review URL: https://codereview.chromium.org/1837393003

Cr-Commit-Position: refs/heads/master@{#35122}

src/compiler/code-stub-assembler.cc

@@ -653,8 +653,7 @@ Node* CodeStubAssembler::ChangeFloat64ToTagged(Node* value) {
     } else {
       Node* pair = Int32AddWithOverflow(value32, value32);
       Node* overflow = Projection(1, pair);
-      Label if_overflow(this, Label::kDeferred), if_notoverflow(this),
-          if_join(this);
+      Label if_overflow(this, Label::kDeferred), if_notoverflow(this);
       Branch(overflow, &if_overflow, &if_notoverflow);
       Bind(&if_overflow);
       Goto(&if_valueisheapnumber);