Discuss diagnostic behavior for statically-known out of bounds access in HLSL

[bob80905]

Consider this shader:

RWByteAddressBuffer gBufArray[4] : register(u0);

[numthreads(1,1,1)]
void main(uint3 tid : SV_DispatchThreadID) {
    RWByteAddressBuffer buf = gBufArray[5];    
    buf.Store(tid.x * 4, 42);
}

There is a statically known out of bounds access.
Currently, clang emits a warning.
This issue tracks the team discussing the diagnostic behavior upon detecting statically-known out of bounds access in HLSL.
Should the diagnostic be a warning? an error? A default error-warning? Does it depend on what is being accessed out of bounds?
This will interact and impact local resource specification.
Should the behavior depend on language version?