[RISCV][Clang] Add some RVV Floating-Point intrinsic functions.

Support the following instructions which have the same class.
1. Vector Single-Width Floating-Point Subtract Instructions
2. Vector Single-Width Floating-Point Multiply/Divide Instructions
3. Vector Floating-Point MIN/MAX Instructions
4. Vector Floating-Point Sign-Injection Instructions

Reviewed By: craig.topper

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Differential Revision: https://reviews.llvm.org/D99668