This gets us the final few cases in the glsl multiplies group.

Test: dEQP-VK.glsl.operator.binary_operator.mul.*
Bug: b/126873455
Change-Id: Id9ec4ad1754a7e63c8d7e0aa0a0b0b156a03b024
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/26651
Presubmit-Ready: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>