DirectXShaderCompiler/tools/clang/test/CodeGenSPIRV/fn.foward-declaration.hlsl

// Run: %dxc -T ps_6_0 -E main

float4 foo(float4 input);

float4 main(float4 input: A) : SV_Target0
{
    return foo(input);
}

float4 foo(float4 input)
{
    return input;
}

// CHECK:  %src_main = OpFunction %v4float None {{%\d+}}

// CHECK:              OpFunctionCall %v4float %foo

// CHECK:       %foo = OpFunction %v4float None {{%\d+}}