Suggest function-local constructors without enclosing function path

[onehr]

Closes #144319

This fixes a mismatched-type wrapper suggestion for constructors defined inside
function-like scopes. The previous diagnostic used def_path_str directly, so a
function-local tuple struct could be suggested as main::Foo(false), even though
main is not a module path that can name the constructor.

The suggestion now prints the constructor path under rustc's existing suggestion
printer mode. That mode omits path segments that cannot be written in source,
while preserving real path segments such as local modules and enum names.

The regression test covers:

• a function-local tuple struct constructor
• a function-local enum variant
• a tuple struct inside a function-local module
• a tuple struct inside a closure body
• a tuple struct inside an inline const block

[rustbot]

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