[llvm] [RISCV] Use f64 for LocVT for ilp32 when whole f64 is passed on the stack. NFC (PR #69118)

[Wang Pengcheng via llvm-commits]

https://github.com/wangpc-pp commented:

Comments at line 17321 are stale?
```cpp
    // IsF64OnRV32DSoftABI && VA.isMemLoc() is handled below in the same way
    // as any other MemLoc.
```

https://github.com/llvm/llvm-project/pull/69118