[llvm] [LoongArch] Add debug location for register reload (PR #122057)

[via llvm-commits]

heiher wrote:

Here is another similar issue:

```
$ gdb ./t
GNU gdb (GDB) 15.1
...
(gdb) b *main
Breakpoint 1 at 0x760: file t.c, line 2.
(gdb) r
...
Breakpoint 1, main (argc=<error reading variable: Cannot access memory at address 0xffffffffffffffe8>, 
    argv=<error reading variable: Cannot access memory at address 0xffffffffffffffe0>) at t.c:2
2	int main(int argc, char **argv) {
```

https://github.com/llvm/llvm-project/pull/122057