DXC crashes on float input with SV_DispatchThreadID semantic

[tristanlabelle]

Repro:

[numthreads(1, 1, 1)]
void main(float3 tid : SV_DispatchThreadID) {}

We should also validate bools and structs, any non-int types.

[pow2clk]

Reopened because fix was reverted https://godbolt.org/z/h59x74rxz

Seeing some weird discrepancies between godbolt and my local windows install. Linux vs windows maybe. Godbolt compiles successfully, which is wrong. Windows crashes, which is wronger.

[llvm-beanz]

Closing since we're not going to address this in DXC.