include/swift/Basic: fix deprecation warnings

[MaxDesiatov]

These are deprecation warnings

include/swift/Basic/type_traits.h:49:29: warning: builtin __has_trivial_constructor is deprecated; use __is_trivially_constructible instead [-Wdeprecated-builtins]
  static const bool value = __has_trivial_constructor(T);
                            ^
include/swift/Basic/type_traits.h:61:29: warning: builtin __has_trivial_destructor is deprecated; use __is_trivially_destructible instead [-Wdeprecated-builtins]
  static const bool value = __has_trivial_destructor(T);
                            ^
2 warnings generated.

[MaxDesiatov]

@swift-ci smoke test

[MaxDesiatov]

@jckarter this apparently reverts your previous commit 1a602e9 that started using these deprecated versions in the first place, would you be available for review then?

[MaxDesiatov]

@swift-ci smoke test

[compnerd]

Do we need to worry about compatibility with older compilers? I think that __has_trivial_constructor is older I believe, so we are going to reduce the compatibility matrix here.

[MaxDesiatov]

Would conditionally enabling __is_trivially_constructible and __is_trivially_destructible, but falling back, when those are unavailable, on deprecated versions be ok?

[MaxDesiatov]

@swift-ci smoke test

[compnerd]

Thanks!