This assert happens when legalizing the operand of an InstAlloca, which
comes from when we want to allocate an IceType_v4f32 on the stack. The
ConstantInteger32 we create has the wrong type, and Subzero asserts.

Bug: b/130459196
Change-Id: I43bd5e516dcd549f5fd35a62ee97cef284a9e656
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/38870
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Antonio Maiorano <amaiorano@google.com>