fix(compiler-core): dedupe renderSlot's default props

[HerringtonDarkholme]

This patch fix the duplicated default props inrenderSlot code generation and simplifies the logic by splicing a default argument array.

Minimal reproduction

renderSlot takes at most 5 arguments but the compiler generates 6.

Note the last argument true should follow immediately after the fallback function.

It looks like an accidental bug that default slotProps is pushed twice when children are defined and SFC has no slotted selector.

Instead we can provide a default arg array, set arguments in their position if defined, and finally splice the array to remove unused args.