[SVE] Eliminate calls to default-false VectorType::get() from Utils

Reviewers: efriedma, c-rhodes, sdesmalen, xbolva00

Reviewed By: c-rhodes

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80337