HLSL parameter passing and call ABI

[llvm-beanz]

This is an umbrella issue for a set of related changes to support HLSL parameter passing.

• Document function calls ([HLSL][Docs] Add documentation for HLSL functions #75397)
• [HLSL] Implement vector extension/truncation/conversion standard conversion sequences #70125
• [HLSL] Array by-value parameter passing #70123
• Mitigate ConstantArrayType size increase #85124
• Parameter InputModifier like in/out/inout #59849
• [HLSL] Overload resolution should promote 16-bit types #81047
• [HLSL] Copy in/copy out parameter passing #87526
• [HLSL] Default literal floating point types to float #85714
• [HLSL] Scalar to vector implicit conversion #90788
• [HLSL] Integer conversion overload scoring #91075
• Document Overload Resolution microsoft/hlsl-specs#232
• [HLSL] inout/out ABI for array parameters #106917