[libcxx] [clang] [Clang][libc++] Implement __is_nothrow_convertible and use it in libc++ (PR #80436)

[Nikolas Klauser via cfe-commits]

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@@ -567,6 +567,7 @@ TYPE_TRAIT_1(__is_unsigned, IsUnsigned, KEYCXX)
 // Embarcadero Binary Type Traits
 TYPE_TRAIT_2(__is_same, IsSame, KEYCXX)
 TYPE_TRAIT_2(__is_convertible, IsConvertible, KEYCXX)
+TYPE_TRAIT_2(__is_nothrow_convertible, IsNothrowConvertible, KEYCXX)
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philnik777 wrote:

There are a bunch more type traits that aren't listed correctly anymore, so IMO an NFC patch that updates them all would be better.

https://github.com/llvm/llvm-project/pull/80436