[RISCV] Add new vector instructions in v0.10.

* Add new vector instructions in v0.10.
 - load/store for mask value vle1.v vse1.v
 - vsetivli for 0-31 immediate vector length.
* Rename vector instructions in v0.10.
 - vfrsqrte7 -> vfrsqrt7
 - vfrece7 -> vfrec7
* Reserve memory width encodings for EEW>128b.

Differential Revision: https://reviews.llvm.org/D95781