target/riscv: rvv: Provide a fast path using direct access to host ram for unmasked...

target/riscv: rvv: Provide a fast path using direct access to host ram for unmasked unit-stride load/store

This commit references the sve_ldN_r/sve_stN_r helper functions in ARM
target to optimize the vector unmasked unit-stride load/store
implementation with following optimizations:

* Get the page boundary
* Probing pages/resolving host memory address at the beginning if
  possible
* Provide new interface to direct access host memory
* Switch to the original slow TLB access when cross page element/violate
  page permission/violate pmp/watchpoints in page

The original element load/store interface is replaced by the new element
load/store functions with _tlb & _host postfix that means doing the
element load/store through the original softmmu flow and the direct
access host memory flow.

Signed-off-by: Max Chou <max.chou@sifive.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20240918171412.150107-4-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>