[interp] Add separate opcode for pop vt (#36760)

[interp] Add separate opcode for pop vt (#36760)

Before this change, pop-ing a vt from the stack was done in 2 opcodes, a MINT_POP (decrementing the stack) and the weird MINT_VTRESULT (decrementing the vtstack). However, optimizations could have removed both the initial loading of the value type on the stack as well as the MINT_POP, leaving MINT_VTRESULT underflowing the vtstack. Fix this and cleanup the code by pop-ing a value type from the stack in a single instruction.

Co-authored-by: BrzVlad <BrzVlad@users.noreply.github.com>