fxc compiles this method even without the backcompat option.
Furthermore, it even does it on ps_2_0 despite the fact that it maps to
a texldd instruction, which is not available on plain ps_2_0, nor ps_2_b,
only on ps_2_a and ps_3_0 according to documentation.
It is worth mentioning that the additional offset parameter is not
supported when lowering.
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