The SPIR-V spec states:
"Coordinate must be a scalar or vector of floating-point type. It
contains (u[, v] … [, array layer]) as needed by the definition of
Sampled Image. It may be a vector larger than needed, but all unused
components will appear after all used components."

Bug b/129523279
Tests: dEQP-VK.glsl.texture_functions.texture.*
Change-Id: I951f679b7794fef5fbbe504c753db052c5cf124b
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/31694
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>