Henrik G. Olsson 5519be8b7c Move span to conditional header in libstdc++ module map ...

`span` is not available in all versions of libstd++, so make it a
conditional header. Also adds other missing c++20 headers.

Fixing this triggered an assert when importing a constant initialized
`wchar_t` variable, so that is also fixed. The reason is that `wchar_t`
is mapped to `Unicode.Scalar`, which cannot be directly initialized by
integer literals in Swift, triggering an assert when looking up the
protocol conformance for `_ExpressibleByBuiltinIntegerLiteral`.

rdar://162074714

2025-10-06 16:02:35 -07:00

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Inputs

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import-cchar-types.swift

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