Add a new langopt NativeInt16Type to control support for 16 bit
integers.
Enable by default for all languages but HLSL.
HLSL defines uint16_t and int16_t as a typedef of short. If
-enable-16bit-types is not used, the typedefs don't exist so int16_t and
uint16_t can't be used. However, short was still allowed. This change
will produce an error 'unknown type name short' if -enable-16bit-types
isn't used.
Update failing tests.
Add new test.
Closes#81779
HLSL extends C++'s requirement that unary `!` apply to boolean arguments
and produces boolean results to apply to vectors. This change implements
implicit conversion for non-boolean vector operands to boolean vectors.
I've noted this behavior in the issue tracking writing the HLSL
specification section on unary operators
(https://github.com/microsoft/hlsl-specs/issues/686).
Fixes#162913
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Co-authored-by: Farzon Lotfi <farzonl@gmail.com>
Co-authored-by: Erich Keane <ekeane@nvidia.com>
