WASM output size increased dramatically after using `finalize_mall`

So after we introduce finalize_mall the size of the output jump from 105988 bytes to 1920836. Here is the repo to reproduce. You could comment out the line 20 in lib.rs and rebuild to see the size difference.

Here is the twiggy output:

 Shallow Bytes │ Shallow % │ Item
───────────────┼───────────┼─────────────────────
       1114182 ┊    50.45% ┊ data[27]
        130051 ┊     5.89% ┊ code[58]
         36760 ┊     1.66% ┊ code[141]
         34324 ┊     1.55% ┊ code[124]
         33238 ┊     1.51% ┊ code[133]
         33160 ┊     1.50% ┊ code[134]
         26996 ┊     1.22% ┊ code[0]
         22455 ┊     1.02% ┊ code[4]
         15285 ┊     0.69% ┊ code[702]
         13561 ┊     0.61% ┊ code[24]
         12668 ┊     0.57% ┊ code[3]
         10724 ┊     0.49% ┊ code[31]
          8538 ┊     0.39% ┊ data[3]
          8232 ┊     0.37% ┊ code[1]
          8226 ┊     0.37% ┊ code[9]
          8226 ┊     0.37% ┊ code[10]
          8226 ┊     0.37% ┊ code[11]
          8158 ┊     0.37% ┊ code[12]
          8081 ┊     0.37% ┊ code[5]
          8074 ┊     0.37% ┊ code[2]
        659305 ┊    29.85% ┊ ... and 2521 more.
       2208470 ┊   100.00% ┊ Σ [2541 Total Rows]
       

Reproduce the size change using the linked miniscript-size-reproduce repository, then inspect lib.rs around line 20 and compare builds with that line enabled and commented out. Use the provided twiggy output to investigate the source of the added data and code; done means identifying and resolving the dramatic WASM output-size regression while preserving finalize_mall behavior.