[PATCH 0/2] RISC-V: Support _Float16 type and implement zfh and zfhmin extension

[Kito Cheng]

This patch set implements Zfh and Zfhmin, adds soft-float for _Float16, and 
enables _Float16 type in C++ mode.

Zfh and Zfhmin are extensions for IEEE half precision, both are ratified in 
Jan. 2022[1]

v2 Changes:
Fix mangling for C++ mode to fit the RISC-V psABI spec.


[1] 
https://github.com/riscv/riscv-isa-manual/commit/b35a54079e0da11740ce5b1e6db999d1d5172768