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Description
the rustc_layout_scalar_valid_range_start
and rustc_layout_scalar_valid_range_end
attributes require a lot of machinery to stay sanely usable. Pattern types don't require less machinery, but they are simpler as they don't break through layers of layouts and then require surprisingly subtle unsafe code to be used correctly.
So we're ripping out the attributes, and replace their usages in libcore and rustc:
std::ptr::NonNull
std::num::NonZero
rustc_index_macros::newtype::NewType
std::num::Nanoseconds