[llvm-branch-commits] [LoongArch][MC] Add relocation support for fld fst [x]vld [x]vst (PR #133225)

[via llvm-branch-commits]

https://github.com/wangleiat created https://github.com/llvm/llvm-project/pull/133225

This also fixes errors when using Clang with step-by-step compilation.
Because the optimization will pass relocation information to memory
access instructions. For example:
t.c:
```
float f = 0.1;
float foo() { return f;}
```
```
clang --target=loongarch64 -O2 -c t.c --save-temps
```