Improve core::ptr::drop_in_place debuginfo

[bjorn3]

• Use span of the dropped type as function span when possible.
• Rename symbol from core::ptr::drop_in_place::<hash> to something like <drop TypeName>::<hash>.

[tmiasko]

The v0 mangling includes information about generic parameters, e.g., core::ptr::drop_in_place::<alloc::string::String>.